Just my $.02:

Windows 7 is a bit schizophrenic at times when it comes to file transfers (and anything in c:Program Files* - where ASLR and DEP kick in the tightest). OTOH, this probably isn't the cause here.

A couple ways to get around it is to find poser.exe, right-click it, and select the "Compatibility" tab. In there, you can make Windows 7 pretend it's XP, Vista, or whatever. Fiddle with it a bit.

Though before you do that, you can also select the "Run this program as as administrator" checkbox, apply it, and see what that does for you.