Blank page in checkout process - Help please

Hi,

I know the subject has been mentioned more than a couple of times, and I have read through the possible solutions, but I am no further.

It concerns the following page

**http://guitaristbackingtracks.com/index.php?main_page=checkout_payment
**
which is where you choose the payment method. The page where you chose the shipping method is working just fine.

So I downloaded the debugger file, and this is the result I get afterwards:

PHP Fatal error: Call to undefined method ot_better_together::get_order_total() in ////includes/classes/order_total.php on line 181

So, I reckon that the error concerns the Better_Together contribution which I have installed

Now here is the thing, I compaired the order_total.php in 1.3.8a and in my 1.3.7.1 installations and these files are complately different, so I am a bit aprehensive to just swop them around.

Can it be that I just have to re-install the contrib??

Can anybody help me out here please? Thanks in advance.

Peter

PLEASE IGNORE THE ABOVE POST AS THE PROBLEM HAS BEEN SOLVED