kitw said:
Thanks for this, Irene. There wasn't an "Exchange Scan" item in the Exchange Client Extensions screen, but there was something similar and a separate entry for McAfee so I disabled both. I also found on the McAfee website that if I opened Outlook as administrator I could deselect the McAfee COM add-on, so I did that too. And it made no difference at all!

So, in the end I've uninstalled McAfee and installed AVG Free, then disabled AVG add-ons. It's working better now, but still performance is poor when sync-ing the Gmail IMAP folders. Looks like I'll have to live with the fact that Outlook 2007 doesn't work that well with Windows 7.

Thanks again for all your help. Much appreciated.
Very pleased to hear that, kitw :)

Another Free Anti-virus worth trying is http://www.microsoft.com/security_essentials/
I use it along with Windows Firewall... I have not experienced any problems whatsoever.