Investigate ActionCleanupDelayFilter triggering

A reported case:

After upgrading from JIRA 3.6.2 to 3.7 i get the following errors in my JIRA log.

2006-12-30 12:19:37,297 http-8080-Processor23 ERROR [jira.web.filters.ActionCleanupDelayFilter] Thread corrupted! ActionContext is not null. URL: 'http://jira.wmdata.dk:8080/int/secure/null'. Attempted to clean up: false

2006-12-30 12:30:40,870 http-8080-Processor21 ERROR [jira.web.filters.ActionCleanupDelayFilter] Thread corrupted! ActionContext is not null. URL: 'http://jira.wmdata.dk:8080/int/styles/combined-printable.cssnull'. Attempted to clean up: false

Though the filter should be stopping any further damage, this shouldn't be happening in the first place.