This is a very strange problem that I have only observed on two occasions in our environment. First was on my own workstation a few weeks ago, I ended up reinstalling Windows for an unrelated problem and this issue went away. Now it's happening again on a different user's computer. Both instances were Win8.1 x64, fully patched, latest TB. The problem: When moving the mouse up and down over a list of emails, the attributes (Subject, From, Date) randomly change to other values for some messages. I've included several screenshots to try and clarify. Between each screenshot, all I did was move my mouse (no clicks or anything else) over them. Notice the subject and date/times changing. I understand the messages themselves are not changing, but it's very confusing for the user. Troubleshooting / Observations: - Reinstalled TB - did not help - Completely removing [...]roaming\thunderbird folder, recreating the user's IMAP account and downloading all mail again - did not help - This problem appears to happen in subscribed IMAP folders and local folders (basically, anywhere there is a list of messages) - Tried compacting/repairing the folders - did not help - Problem is not happening on user's linux workstation, only on windows. - User says the problem has been happening for a week or so - When I run in safe mode, the problem goes away! BUT when I disable all add-ons, reset toolbars, and run in normal mode again, the problem returns. To clarify, there are no add-ons enabled currently and the problem is still happening. What's different between running in safe mode, and running normally after disable all add-ons and resetting all toolbars, etc? I'm at a loss and I really don't want to reinstall the OS to try and fix this! Any ideas? Thanks for any help!