The factors you've missed out of your list are the versions of IE and the Flash Player/Plugin (as these are effectively part of Poser's library system).
It's also possible that you've got stuff like Windows Defender that would have come in via Windows Update.<<

As I said, it was a clean install of Windows 7. From there I installed Vue 8 Infinite, then Poser. Whatever Windows 7 from microsoft turns on by default (win defender, firewall, IE8, etc) was loaded, yes. Windows 7 does NOT install Flash, but Poser may and of course if you open IE and visit almost any page you'll be prompted to install Flash.

So while I'm not going to screw around with my system to test it out (because I'm not paid to do so), it seems pretty easy to replicate the path... do a clean install of Win7, install Poser 8 and see what happens. Nothing? Kick up IE8 and install the latest flash. Nothing?

If one wanted to introduce Vue 8 Infinite that would be next.

That's basically all the items, software wise, that all that would be in the mix: Win7, IE8, flash, Poser and in my case Vue 8 Infinite. There's obviously sub issues like Win Defender yes but that's part of the base Win7 package. And the base firewall setups in Win7.

My point is... ONE of all of those are the key elements. Because one of those triggers the temp file creation.