Just Installed Leopard Mail Crashes on Open

Hi, I just installed leopard its version 10.5.0 and everytime I open mail it opens on the dock and then dissappears and I get a Mail quit unexpectantly message and when I click report I get this:

Dyld Error Message:
Symbol not found: __CSAOSCopyStringForKey
Referenced from: /System/Library/Frameworks/Message.framework/Versions/B/Message
Expected in: /System/Library/Frameworks/CoreServices.framework/Versions/A/CoreServices

Did anyone else have this problem? I did a clean install and I have tried reinstalling Mail from the OSX Disc and it still has the same problems. Ive also done repair permissions which still doesnt fix it. Will I have to reinstall OSX to get Mail to work? If anyone else had this problem and updating OSX fixed it please let me know, Im still on dial up so the 10.5.4 update is kinda big so i'll have to go down to the internet cafe to download it there. I just need to know wether im going to have to reinstall OSX or update it when I get the chance.

I think I just found out what is going on, I install the mobileme.pkg but i didnt try to run Mail before to see if it was working, I dont have a lot of spare time to go and download updates. Is there anyway I can uninstall mobileme?

Thanks

Unfortunately I think the first thing anyone is going to say is to do the update. Just in case it doesn't work, for some reason because of the mobileme thing, I would download the combo update from the website and either burn it to a disc to otherwise copy it so you don't have to redownload it again later.

Hi, its working great now, everything actually opens now I think it was because I install the mobileme package when my computer was under the OS version required so now that its updated it works fine! Thanks so much. I can get my mail now.