Google Maps not working correctly with my theme

Hello,
I'm very confused and frustrated, because the map is not showing. I only get a grey field with the icon.
Except with safari! It's working on iPad/iPhone.
I know it's a problem with my theme but I can't find the reason.
I enabled debug mode and solved every error mentioned in the error log - didn't help.
I disabled all custom javascript - didn't help either.

I hope you have an idea to solve this problem.
Look here: http://engel-online.de/anfahrt/