Upgrading to Leopard

Upgrade.  The very word echoes sentiments of new amazing features solving my every concern.  So last week we took the plunge upgrading to Leopard for Mac.  Albeit pushed over the edge slightly by the fact that our upgrade to QuickBooks ’09 wouldn’t work with Tiger.  
Installation went well although taking over 30 minutes.  And it was a bargain at $169 for both the new OS coupled with iLife & iWork ’09.
There was a problematic glitch after the OS loaded.  I launched Mail but the app only partially responded.  It wouldn’t open the Mail window and none of my messages appeared.  I checked the settings and accounts in preferences and everything was ok.  What to do next?
After googling the problem, I found this link the most helpful in correcting the issue and getting the upgrade back on track:
Apple Mail Upgrade Leopard Crash
After I removed then replaced the files everything worked fine.  Although I’ve yet to experience the full bells and wistles of the new OS, it does seem a bit easier to navigate.
Hopefully this will help if you’re having the same issue!