Seamonkey crash leads to mixed-up profiles

I switched from Firefox to Seamonkey due to Sage not being actively developed, and now I'm staying with it. While I had it installed locally for a few months, I switched to Portable so that I could keep current with email and RSS feeds when I wasn't on my own computer.

A while back, Seamonkey crashed for some goofy reason. When I opened it again later, things seemed fine.

I rebooted again later and, after opening Seamonkey again, found that an old newsgroups account I had created and deleted came back, and some feeds that I had added afterward were missing.

After closing and reopening it, I noticed that things were normal. However, it would occasionally switch back to the old profile when I closed/reopened.

I figured out that Seamonkey left some profile files behind in AppData. After deleting what was there and copying over my profile files from my external drive, it's been working normally.

My question is, does Seamonkey use copy+delete to manage local profiles? I'm not sure, but my guess is that Seamonkey copied the profile files and was unable to delete them later due to the program crashing. Is there another way to manage profiles to keep this from happening?