Internal Server Error using Quick Books (Intuit) pay module

[johng_yds]

I m using Zen Cart 1.3.8a with MySQL 4.1.20-standard on an initial install. Added "Glacial Ice" template and Quick Books (Intuit) pay module.

Now for the problem, after testing and checking all seemed to be working well. When I went on line to the public I decided to try an order myself. What happened is goofy and not good. My order went through my pay agent and received valid authorization, but instead of getting the standard "thank you" for your order. I received the following error message:

Internal Server Error
The server encountered an internal error or misconfiguration and was unable to complete your request.
Please contact the server administrator, [email protected] and inform them of the time the error occurred, and anything you might have done that may have caused the error.
More information about this error may be available in the server error log.

Since then the problem continues with no respite in a live or test situation.

Searched a large amount of the FAQ'a and the forum here and could not find a thing related to this. Any Ideas! please be gentile --- I am not the brightest bulb in the bunch when it comes to using all this php, Mysql, Zen Cart but I am learning.

Thanks,

JJG:(
YourDieselSolutions.com