Opera is driving me crazy with Gmail account

Opera is driving me crazy with Gmail account

First of all....
- I use Opera 11.60 on XPsp2
- I've reinstalled Opera many times, after renamed old one in order to have a true new installation
- I've checked HDD and defragmented it.

I have many POP account working perfectly and one Gmail IMAP account that is driving me crazy, because...:
- has deleted all emails on gmail server
- replicates received and sent email many-many-many times (some over hundred replications)
- when I delete duplicated mail it crashes
- when I exit the program it always crashes (if I use opera without mail, with -nomail switch, never crashes)
- folders within gmail label change every time and some cannot be activated some cannot be de-activated, same in account config
- Opera keeps generating thousands of empty mails burdening the system and while I delete them it creates new ones...
- lots of warnings and errors from email server and java (unistalled all version and installed latest one from Java.com)

MOZILLA mail client works perfectly with this gmail account !!!

I use Opera since '94 but now I can't stand it any more. I patiented for months but now I'm really ANGRY since IT DELETED ALL MY FILE on gmail server and cannot get it back since I did not know what it was doing when I emptied the basked...

Opera, what I thought was the best browser, has been demolished...