did anyone ever figure out how to fix the corrupted save game issue

[McDonnel]

I must say I had the same problem with GWX - crashing loaded careers on "Not so long ago..."...

and very infuriatingly, saves from single missions didn´t. After few days of unsuccessful tries, I gave up and decided to give try to LSH3.

There, during the installation process, was a simple troubleshooting guide:

When crashes occur at career loadings, make sure you have SH3.exe set on Windows 7 compatibility and running as administrator.

I told to myself, oh what the hell, you have reinstalled SH3 with GWX so many times, one more will not hurt you - did clean install, clean GWX install, performed the setting and...

Lo and behold, GWX issues with career loading solved. No corrupted saves anymore, I can save any time, any amount of contacts - middle of exploding convoy, exploding harbors when I tried deck gun barrage just to test it are not problem anymore etc.
It loads perfectly fine now.

Check your compatibility for Windows 7 and running as admin