If you are having trouble getting your site to verify there are a few reasons why this could be happening. Please see our tutorial to help troubleshoot the causes: Why is Google Webmaster not verifying?
You may also find these articles useful:
I'm trying to verify my site with Google Webmaster and it's not working, why?
When I change my domain, do I need to verify my site again with Google Webmaster?
How do I verify my site with Google Webmaster?