I've been using OSCommerce on LP for around 4 years. I've been using the built in Authorize.net contribution to process credit cards for the last 3. Problem is, very sporadically I receive a "General Error" in my authorize.net transactions.

The customer clicks submit in OSCommerce and it instantly logs them out. Leaving them a little confused but they assume it processed correctly. In OSCommerce admin their order shows up as Pending. I didn't know until after a few years that we were periodically receiving this error and not being paid for those transactions. After doing more research it appears it was happening at least a few times a month and sometimes on big ticket orders. Needless to say, that's a big problem for us - we need to eat.

I've contacted LP in the past and they said it looked like a problem on Authorize.net's end or possible a problem with OSCommerce. Contacting Authorize.net they always claimed it was the server not aknowledging reciept of the message. OSCommerce code looks fine on the script and only a small handful of people have reported the problem. Unfortunately none were able to fix it other than just checking their authorize.net logs daily to catch the issue before the order shipped. Unfortunately calling them up yeilds about a 30% failure to pay due to concerns about our site security or phone scams.

Authorizet.net claims that these transactions were receiving a code 52 error (no response from server). The OSCommerce code for the error isn't being fired off or they would receive an error message and the order wouldn't be successful, not just a sudden logoff. Apparently Authorize.Net is waiting 10 seconds to receive acknowledgement of the transaction start. Problem is that it doesn't take that long so they said that the server must not be accepting the message at all.

I can track the exact time of the transaction occurances but it's been of little use so far as no one seems to take us losing a few thousand in sales / quarter seriously to actually follow up in detail. Is anyone else having this issue? Any suggestions on fixing it?

The only other mentions of the issue I've found is at: http://forums.oscommerce.com/index.php?showtopic=199381 but no solutions were found.