User Agent: Mozilla/5.0 (Windows NT 5.1; rv:12.0) Gecko/20100101 Firefox/12.0 Build ID: 20120420145725 Steps to reproduce: I changed the parameter settings regarding columns ("Date", "Size", etc.) in the Inbox mail list and applied these parameters to the other folders using the appropriate selection ("Apply to folders and subfolders"). Actual results: After a while (next restart of Thunderbird, the day after, I would say), my parameter settings were reset, apparently to their default values, without any visible explanation. Expected results: Parameter settings shouldn't have changed on their own... :-)

(In reply to David Bourguignon from comment #0) Not sure if this is related to bug 749574.

Red arrows pointing at the columns. "Follow" and other default columns can reappear at next restart, even after removing them from the options list.

Hi Hashem, thanks for the feedback but I don't think this bug has something to do with folders display... See the screen capture I've added for a better explanation of the problem. Thanks in advance for your help!

I also think this is very similar (maybe same) to bug 749574. David, what do you think is different?

Thanks :aceman for your message. As far as I understood the description of bug 749574 this has to do with email folders display and not properties columns ("Receiver", "Date", "Size", "Read", etc.) display. Therefore, the effect is totally different... :-) Thanks in advance for your help!

Can you see in Tools->Addons if you have the Test Pilot extension enabled? If yes, can you try disabling it?

Thanks :aceman! I switched Test Pilot off: let's see how it goes... I'll get back to you within a week with fresh news. Thanks in advance!

Hi :aceman, after switching Test Pilot as I said, unfortunately, the problem showed up again... Therefore, the bug lies elsewhere I'm afraid. Thanks in advance for your help!

Thanks Hashem! This is a duplicate indeed. Have a good day!

Dupe of bug 710056?

Yes Chris, it looks like the same bug indeed... By the way, I also read this in the bug description: "The profile is very old, could that be some artifact breaking this?" In fact, I have not reinstalled Microsoft Windows XP for years on my PC... Could this be related? Refreshing the OS and my Mozilla Thunderbird installation is on my TODO list. I will do it in a few weeks. Thanks again for your help!