Actually MioM, I'm having the exact same problem, and I'm using Diablo II with the LoD Expansion and 1.09 patch, battle chest version though, might be some difference.
well Lucinate, do you get a popup before the corrupt field popup, saying "JM Signature not found" and then the corrupt field popup reads "Corrupt field encountered in save game file! (@ offset 2402)"? something wierd is going on, hope someone can help you, unless you do have 1.10
