Here's the issue:
The current GPO is able to push out the old software out without a problem, and also doesn't let users uninstall it. This is perfect, this is what I want. However, as soon as I add any new software, the new one won't install. They all come from the same folder, same privileges, pretty much same everything but it still doesn't let me. I've done a gpupdate, restarted, made sure there weren't errors on the logs... I really don't know. =[