My site is giving off the "Error - could not load the required payment module! Please contact the owner of this blog to get the issue resolved!" as well with 2.07. Everything was perfectly fine with 2.05.
If you open the file called purchase.php and look for the line that starts ksort, and change it to sort, that should fix it for all future purchases.
If you've got any existing ones that are failing, you'll need to open the purchase up in the admin editor and select the right payment method, then save.
Sorry about that, I temporarily uploaded the wrong file and a couple of people grabbed the bad version before I realised and changed it back.
thanks Simon
Works now:)
Thanks Simon, everything works now (that I know of :)).