Innaccurate Google Event Tracking

Has anyone noticed inaccurate data in Google Analytics Event Tracking? I’m using the method described below and the numbers aren’t matching up to my other data.

http://contactform7.com/tracking-form-submissions-with-google-analytics/

It seems as though it may be a time delay issue, where the Event is only being fired if the form submit time allows?

http://wordpress.org/plugins/contact-form-7/