I had some problems with Google Maps V3 on Drupal 6, so I made a patch with a few fixes.
Be aware that this removes support for the V2 API, so it's not for everyone.
Thanks for the patch. It seems to still be missing the "https:" on the front of the src attribute however, and I don't know if "library=places" is needed, but I added it in my copy. The total result is: $url = 'https://maps.googleapis.com/maps/api/js?sensor=false&libraries=places&v=3.2';
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