Production error: "org.postgresql.util.PSQLException: ERROR: deadlock detected"

[793546160] errors.GrailsExceptionResolver Exception occurred when processing request: [POST] /productVersionDropDown/selectedForTranslation
Stacktrace follows:
org.postgresql.util.PSQLException: ERROR: deadlock detected
  Detail: Process 17234 waits for ShareLock on transaction 3122817; blocked by process 16620.
Process 16620 waits for ExclusiveLock on tuple (16,51) of relation 24072 of database 24021; blocked by process 17234.
  Hint: See server log for query details.
        at org.postgresql.core.v3.QueryExecutorImpl.receiveErrorResponse(QueryExecutorImpl.java:2103)
        at org.postgresql.core.v3.QueryExecutorImpl.processResults(QueryExecutorImpl.java:1836)
        at org.postgresql.core.v3.QueryExecutorImpl.execute(QueryExecutorImpl.java:257)
        at org.postgresql.jdbc2.AbstractJdbc2Statement.execute(AbstractJdbc2Statement.java:512)
        at org.postgresql.jdbc2.AbstractJdbc2Statement.executeWithFlags(AbstractJdbc2Statement.java:388)
        at org.postgresql.jdbc2.AbstractJdbc2Statement.executeUpdate(AbstractJdbc2Statement.java:334)
        at translate.TranslationService.saveTranslation(TranslationService.groovy:433)
        at translate.TranslationService$_prepopulateWithSuggestedEntries_closure6.doCall(TranslationService.groovy:247)
        at translate.TranslationService.prepopulateWithSuggestedEntries(TranslationService.groovy:220)
        at translate.TranslationService$prepopulateWithSuggestedEntries.call(Unknown Source)
        at translate.ProductVersionDropDownController$_closure1.doCall(ProductVersionDropDownController.groovy:75)
        at translate.ProductVersionDropDownController$_closure1.doCall(ProductVersionDropDownController.groovy)
        at com.studentsonly.grails.plugins.uiperformance.CacheFilter.doFilter(CacheFilter.java:67)