terms and conditions issue

[info@nslimming.com]

I have spent 4 days trying to workout what the problem is and trawled through countless threads, but non seem to fit the repair I require. I am unfortunately not familiar with heavy code.

On the old site www.nslimming.com the during virtuemart checkout , if you select a product and proceed to checkout without entering the terms and condition-> it forwards you to the registration form -> on completion it logs you in. On completion of this -> it then forwards you to accept the terms and conditions on accepting this, it proceeds to select a shipping type-> success.

On my new site www.natural-slimming.com during checkout if you select a product and proceed to checkout without entering the terms and condition-> it forwards you to the registration form. On completion and clicking 'register button' the code seems slow, and you either receive a time out error or you double click on the button register button and receive the error of the 'user already in use' and make a total mess of the registration.

I believe it is a vm to Joomla code problem I would be grateful if anybody can point out the actual problem between the two and provide a solution to get the new site working.

Note I have clean installed Vm on the problem domain (hence there only being one product) but the problem still persists. I have also switch hosting servers to. Both shops have the same setting chosen in the back end.

Joomla v 2.5.14
VM v 2.0.22a