Looks like you have some funky cache stuff going on.
Can you deactivate the caching plugin you’re using, and see if it fixes the issue?
If it does, you may have to re-set the caching settings, as it may be remembering your old theme. I know of a few users using W3 Total Cache successfully with GP, so it may just be a matter of manually choosing the files to minify etc..
Let me know 🙂