I am using 1.3.7.1 (Yes, I am waiting for 2.0 to come out to upgrade) and it has been running smooth for a long time. All of the sudden, the Sage Payment module stopped working on 3/4/9. After the customer enters the credit card info on step 2, instead of validating the card it just reloads the step 2 page.

I have enabled the offline credit card module in the meantime.

Any ideas?
Thanks