Some customers signed up with us yesterday said that they could not pay us as 2Checkout recurring billing routine denied their credit cards although they use their own CC. In fact, they went through all security check when they ordered domain names, cart billing routine accepted their credit card and processed their orders but when they came to recurring billing they could not get through. I just wonder is it me or 2checkout has problem, I also contact 2Checkout but they haven't replied so far (12 hours). Anyone knows anything about this?

I've not had a problem with it before. Is this the first recurring billing you've attempted to process? Is your account in test mode, by any chance? Do you know what sort of error was produced?

No, I'm pretty sure that either 2Checkout or my customer's credit card has problem as this is not our first time billing. I also got reply from Tom at 2C/O but he didn't clarify anything.