Yes I have had a similar issue happen to me. It only seems to happen in 1.00 (not 1.06 or later). Whenever I went into MP to mule, the game crashed on one instance. The other disconnected. Thankfully nothing was lost or duped.
Not sure what the options are to prevent this. The only decent program for D2C is Jamella, and it's a character editor as well. But that could be a way to mule.
Difficulty Bug: I was rushing a barb with my sorc to Act 4 for maggot leveling. My sorc had beaten Normal and was able to go to nightmare. But after I exited out of the TCP game, the sorc lost her ability to go to nightmare. I think the quest state from the mule bugged my sorc so she was stuck on normal. Now, to fix this, I found a (non-FAM?) way using Jamella:
1) Backup character to be safe and open in Jamella
2) Select character stats page
3) Change max difficulty back to the way it was before the game bugged (N, NM, H, H Done)
4) Save and if it didn't fix it restore backup
@helvete The drops in Classic are really linear I've noticed. When taking the same path and killing the same monsters in every game, they usually drop the exact same items. This happens to me for uniques, regular, council members, etc. To bad this isn't the case in LoD!