skarre - i was running into the same issue - try this - Confirm that you've installed the plugin, and that you are not getting any errors in your "Plugin" section in WordPress (while logged in as admin). Then double-check that the plugin is currently activated. If all this looks good, then completely LOG out of the WordPress admin section - close all open browsers, and then open a new browser and access your blog web site.
The problem that was happening to me is that i was trying to check google while i was still logged into WordPress as an admin - if you do this Google will report back that it can't find your analytics code - that's because it's NOT there - and it's by design. It's built that way so that analytics won't count your admin visits as actual valid "hits" to your site. When you access your site, view the source (in Firefox - "View" > "Page Source"...in IE - "View" > "Source") and see if there is a section in there like this:
<!-- Begin Google Analytics Code by Local Analytics Plugin -->
If so, the plugin is now working - if you then log into google analytics, you should see that it's accurately monitoring your site for statistics.