Authnet: An error occurred while trying to report this transaction to the merchant.

Well - good news. We switched to the new hosting service. After transferring all the files over and getting the database reloaded. Everything works like a charm!!

And this is still using the Authorize.net SIM module. With no SSL. Works fine, but we will be upgrading to SSL and AIM soon, just for security issues

Just thought I would post back up and let you know that it was definitely some problem with the hosting service and the configuration of the server.

Everything is working great now. Thanks again for all your help with this perplexing matter.

Thank you for the follow up and letting us know it was definitely a hosting problem.