means that the cache manager tried to delete the file, but couldn't, because some other program was using the file.<

If i had to guess it's not anti-malware but rather some service like Volume Shadow Copy or UAC that's preventing the file from being removed, or that's logging this entry and not preventing it from being removed.

I don't know enough about all the windows services to really dig too deep, but I know those two alone if enabled (and they are on most people's machines) can cause ... how do I phrase this... troublesome.... issues.

With UAC i've seen instances of applications not being able to permanently store config files or registration/serial/activation issues (Vue and others comes to mind). With VSS I've seen cases where files say they are in use but I know for a fact they really aren't. And of course you can delete them but you really aren't deleting them. Until they get deleted... hehe.... it's very weird.

And there's hundreds of services like this just on windows alone. Mac I don't know.

I know for fact I have windows defender off and no AV app turned on. (Win keeps bugging me about it too). I've also tried shutting off various other 'logging' type services but to no avail.

However, I will say I've NOT yet tried turn back off UAC and watched what happens with Poser. I'm sure I've tried it before but now I can't say for sure. Going to give this and some other ideas a try.