Recover Outlook PST files
Have you tried SCANPST.exe - its part of the office install and is used to recover corrupt PST's Sometimes known as the inbox repair tool The common install path is
C:\Program Files\Microsoft Office\Office12
See the official Microsoft page for some more info on this and a possible solution using Outlook 2007:
http://support.microsoft.com/kb/932086
There's also a bunch of free/commercial tools for splitting PST files, e.g:
http://www.splitpstfile.com/