Bob,
Yes I used to get that also. The customer would actually have a transaction in authorize.net however there would be that red bar at the top of my site. Change the code in authorize_direct.php to just authorize only. Also check in your setting with authorize you should no have any redirect pages listed and one direct connect page which is checkout_process.php. I changed it back to this way and I no longer get the error.
I am working on a way so that you don?t have to go to authorize.net to capture the funds. I have not yet found where the bug is, however he can not hide forever. It is probably something simple and I am staring right at it, however so far it eludes me.
Lates
Pendar