Workaround: check "Enable Minification on External Files" in the advanced 
WP-Minify settings (you have to click Show Advanced Settings at the bottom). 

The workaround has been verified, but this thread may present another 
alternative just in case: 
http://omninoggin.com/forum/wp-minify/wp-minify-is-put-straight-after-ltheadgt/

[deleted comment]

Another workaround report from a user:

I found that using the "Enable Minification on External Files" option in 
WP-Minify ended up breaking a post rating plugin I'm also using.

As a workaround, I instead added the link to the Google JSAPI (e.g. 
http://www.google.com/jsapi?key=WHATEVERYOURAPIKEYIS&ver=3.0.1) directly into 
the "JavaScript files to include into minify" box.

Geo Mashup seems to work fine now.

I am using Better WordPress Minify rather than WP-Minify (because WP-MInify 
broke the sliders on Popular Posts, Recent Comments etc). Now I find that the 
map does not display. I looked in the BWP Minify options for something 
resembling enable Minification on External Files, but could not see anything.

I will try putting the Google key URI suggested into header minified scripts, 
but if anyone has any better advice, that would be wonderful.

Thanks

Jeremy