X-Cart forums - Internal Error

Suddenly, with no changes made by us or our host or our processor, our online customers are getting this error after they enter their credit card info. It is as if the system is timing out then responding with that error code.

"Internal error Please, return to Shopping cart".

When I look at X-Payments for the specific transactions it simply reports the following:

The status indicating that the payment gateway has been asked to make the payment, but the result is not known yet (the payment gateway has not answered or the admin has to process the payment manually).

Transaction list
Jan 24, 2014 22:46:55
Type: Sale
Result status: Unknown
$ 13.18 Transaction failed

I should mention that I am using Version: 1.0.6

Any clues?