Wildcard search does not work if prefix is over 14 characters

If I search for a summary using prefix-wildcard search and specify prefix larger than 14 characters, the result will be empty even if there are matching issues.

Example:

http://jira.atlassian.com/secure/IssueNavigator.jspa?component=10480&summary=true&pid=10240&type=2&reset=true&show=View+%26gt%3B%26gt%3B&query=%2BgetFieldsForCr*

shows JRA-11597, which has "getFieldsForCreation()" in the summary. we search for "getFieldsForCr*", 14-character prefix + wildcard

http://jira.atlassian.com/secure/IssueNavigator.jspa?component=10480&summary=true&pid=10240&type=2&reset=true&show=View+%26gt%3B%26gt%3B&query=%2BgetFieldsForCre*

same request, with one letter added to the prefix - the result set is empty