When clicking on the "Time Spent" tab in the activities section of an issue, clicking on another link (ex, Dashboards) bring up a prompt in all browsers asking if we're sure we want to navigate away from the page.
http://imgur.com/6D6TH

Steps to reproduce:

1) Select an issue
2) Select the All or Time Spent tab in the Activity section
3) Navigate away from the issue. (ie. select dashboards link)
4) Notice the below message.

This was not an issue on our previous version (JIRA 4.4.4, Minyaa 3.3.1). Also, I am not sure if it is related, but everytime we select either the All or Time Spent tab, this entry shows up in catalina.out:

2012-07-13 09:51:34,830 http-80-8 WARN username 591x29581x1 xiw3qt 1.1.1.1 /browse/IS-5984 [plugin.report.workload.AbstractWorkloadHelper] Report Component Class [class java.util.Date] not yet supported ...