I also had the same problems mentioned above (using WordPress 3.3.2)
– GA for WordPress plugin installed but no Google Analytics dashboard not showing visits
– tried re-authenticating but had error messages from Google
Eventually uninstalled the plugin and put the tracking code in the header manually.
This also seemed to solve another problem that I had been having, that whenever I edited the header.php file all my plugins were de-activated and I had to re-activate each one. May be co-incidence but the early signs are that the admin is more stable without this plugin
