Thunderbird v. 3 change my dates (Gmail IMAP) how to fix it?

Hello:

I've been using portable apps from a long time ago without problems.
I have an a Gmail account with IMAP protocol which use in my house, office or portable version without a hiccup until... I tried Thunderbird v. 3 and this is what happened:

After testing this version and see that some addons and Lighting won't work I decided to put on hold more time for this version.

My Thunderbird machine (2.0.23) is working fine and downloading mail as usual, but when I logged to see and archive or delete some spam mail in the web client I saw that the mail wasn't downloading and was mis-syncronized (I don't know if this term exists) but the idea is that the date of the Thunderbird mails and the webclient wasn't the same.

I don't know what else to do... for example mail from 09/02/2006 in the webmail (seen the whole mail with details) and shows as December 21 2009 when I see all the mails in the inbox. The mail in the Thunderbird client looks fine.

Question:
Is there any way to fix these date errors? or nothing to do?

Please any idea or comment is welcome.

Best Regards.