Error in edit issue in GreenHopper 2.1.1

We sometimes get the following error when editing issues after we updated to GreenHopper 2.1.1. This is very annoying since it seems to also remove the issue from the index. Hope you fix this ASAP!

2008-02-14 08:53:40,494 http-8090-Processor15 ERROR [web.action.issue.EditSubTaskIssue] Exception occurred editing issue: java.util.NoSuchElementException
java.util.NoSuchElementException
at java.util.TreeMap.key(TreeMap.java:1206)
at java.util.TreeMap.firstKey(TreeMap.java:267)
at com.pyxis.greenhopper.jira.customfields.RankingCFType.getPreviousPosition(RankingCFType.java:307)
at com.pyxis.greenhopper.jira.customfields.RankingCFType.updatePosition(RankingCFType.java:228)
at com.pyxis.greenhopper.jira.customfields.RankingCFType.updateValue(RankingCFType.java:121)
at com.pyxis.greenhopper.jira.customfields.RankingCFType.setNewIssuePosition(RankingCFType.java:161)
at com.pyxis.greenhopper.jira.customfields.RankingCFType.updateValue(RankingCFType.java:107)
at com.atlassian.jira.issue.fields.CustomFieldImpl.updateValue(CustomFieldImpl.java:351)
at com.atlassian.jira.issue.fields.CustomFieldImpl.updateValue(CustomFieldImpl.java:312)
at com.atlassian.jira.action.issue.IssueUpdate.doExecute(IssueUpdate.java:59)
at webwork.action.ActionSupport.execute(ActionSupport.java:153)
at com.atlassian.jira.action.JiraActionSupport.execute(JiraActionSupport.java:54)
at com.atlassian.jira.action.JiraNonWebActionSupport.execute(JiraNonWebActionSupport.java:27)
at webwork.dispatcher.GenericDispatcher.executeAction(GenericDispatcher.java:132)
at com.atlassian.core.action.DefaultActionDispatcher.execute(DefaultActionDispatcher.java:36)
at com.atlassian.jira.web.action.issue.EditIssue.doExecute(EditIssue.java:197)
at webwork.action.ActionSupport.execute(ActionSupport.java:153)
at com.atlassian.jira.action.JiraActionSupport.execute(JiraActionSupport.java:54)
at webwork.dispatcher.GenericDispatcher.executeAction(GenericDispatcher.java:132)
at com.atlassian.jira.web.dispatcher.JiraServletDispatcher.service(JiraServletDispatcher.java:211)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:252)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
at com.atlassian.jira.web.filters.AccessLogFilter.doFilter(AccessLogFilter.java:73)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
at com.opensymphony.module.sitemesh.filter.PageFilter.parsePage(PageFilter.java:119)
at com.opensymphony.module.sitemesh.filter.PageFilter.doFilter(PageFilter.java:55)
at com.atlassian.jira.web.filters.SitemeshExcludePathFilter.doFilter(SitemeshExcludePathFilter.java:38)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
at com.atlassian.seraph.filter.SecurityFilter.doFilter(SecurityFilter.java:192)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
at com.atlassian.seraph.filter.TrustedApplicationsFilter.doFilter(TrustedApplicationsFilter.java:114)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
at com.atlassian.seraph.filter.BaseLoginFilter.doFilter(BaseLoginFilter.java:110)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
at com.atlassian.util.profiling.filters.ProfilingFilter.doFilter(ProfilingFilter.java:132)
at com.atlassian.jira.web.filters.JIRAProfilingFilter.doFilter(JIRAProfilingFilter.java:16)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
at com.atlassian.jira.web.filters.ActionCleanupDelayFilter.doFilter(ActionCleanupDelayFilter.java:43)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
at com.atlassian.jira.web.filters.RequestCleanupFilter.doFilter(RequestCleanupFilter.java:50)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
at com.atlassian.johnson.filters.AbstractJohnsonFilter.doFilter(AbstractJohnsonFilter.java:72)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
at org.tuckey.web.filters.urlrewrite.UrlRewriteFilter.doFilter(UrlRewriteFilter.java:350)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
at com.atlassian.gzipfilter.GzipFilter.doFilter(GzipFilter.java:81)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
at com.atlassian.core.filters.AbstractEncodingFilter.doFilter(AbstractEncodingFilter.java:37)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
at com.atlassian.jira.appconsistency.db.DatabaseCompatibilityEnforcerFilter.doFilter(DatabaseCompatibilityEnforcerFilter.java:39)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:213)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:178)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:126)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:105)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:107)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:541)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:869)
at org.apache.coyote.http11.Http11BaseProtocol$Http11ConnectionHandler.processConnection(Http11BaseProtocol.java:664)
at org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:527)
at org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFollowerWorkerThread.java:80)
at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:684)
at java.lang.Thread.run(Thread.java:619)