I can always tell when it's time to restart Outlook

If I leave MS Outlook 2007 open too long, it starts to act screwy.  First, it starts to become unresponsive – making the rest of the computer slow, too.  Then, content in the Preview Pane either updates slowly or doesn’t show content at all.  Clicking between folders sometimes helps, but eventually even this doesn’t do a thing.

Windows Vista simpy doesn’t have to be restarted or the computer rebooted due to an OS lag like earlier versions of Windows.  But, MS Outlook — that’s another story altogether.  What’s it going to take to fix this thing.

I thought, possibly, that my PST was getting too fragmented, so I went as far as to create a brand new PST and migrate everything to the new one (the PST had been upgraded from Outlook 2003).  No luck.

I even take time to run maintenance on my PST consistently, i.e., delete unneeded emails from the Sent Items folder, save attachments outside of Outlook in special folders, archive constantly – sometimes manually.

So, I’m in a predicament where I have to shutdown (sometimes using Task Manager) Outlook every 5 or 6 hours.  Crazy and frustrating.  And, it always seems it happens at the times when I’m most busy and have much to do within the Outlook interface.

So, what’s the cure here?  MS’s patches to Outlook and Office haven’t really helped.  Is it time to look to another email client?  Do other email clients have this problem?