One Page Checkout not working when enabled in Admin

[likrish]

I recently came across a problem with the latest version of Virtuemart (and latest version of Joomla).

With one page checkout enabled initially the site was working fine, however I wanted to test with OPC disabled. Once I had completed testing I re-enabled OPC on the back end, however this has had no effect and I am stuck with the step checkout process. I cleared the cache and double checked my settings.

I have no idea why this is not working...
Hoping someone has come across a similar issue!

[jenkinhill]

Have you got both One Page Checkout enabled and Ajax for OPC selected on Config/Checkout?