Actually, it looks like I get this no matter what, now…

Just crunching and crunching and crunching. No javascript errors.

Not sure what was happening here, but a refresh of the themes page and completely different names for both required fields did the trick.

Glad you got it fixed.  We have seen the crunching, and it usually happens when there is a mismatch between the namespace value and they type of org you are in. 

If you are in a packaging org with a namespace - You HAVE to provide the namespace for the theme. 
If you are in a normal org - You MUST NOT provide a namespace for the theme. 

Thanks for your feedback…