Some pages in JIRA 3.0 are starting to exhibit problems under Internet Explorer due to Internet Explorers botched understanding of the CSS Box Model. (See screenshot for example).

I would recommend including a doctype on all pages within JIRA. Choose one that switches on "Standards Compliant Mode" for Internet Explorer: ->

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnie60/html/cssenhancements.asp

By making this switch, Internet Explorer should behave more along the lines of Mozilla/Netscape/Opera/KDE/Safari.

Note: after making this switch, - other layout issues may become apparent (such as center/left alignment). (There will likely be a raft of other small issues come up).