Products or categories?

I have another issues appearing. Check out:

www.northgatetraining.co.uk

the menu is on the left hand side and when you click on the Teamwork plus sign and open the menu there is a blank entry after the first entry. Where is this coming from. There is no blank in my virtuemart and all the other products within that category are listed correctly. Where is the menu pulling this blank url from?

Please help this is a LIVE site and I need to find a solution.

Regards

Lee