Taxes causing incorrect amount to be sent to gateway

[eyestuffguy]

Hello All,

 

I've had a hell of time with this one.

 

For orders that we tax on (GA, FL, TX) the amount that Authorize.net receives/processes is slightly off (less) than what it should be.

 

For example, an item that cost $307.88 is taxed at 8.25% for a total of $333.28. That correct dollar amount is stored in the OSCommerce order but the total that Authorize.net processes is $332.22. In this case it's off by about -.34% for some reason. However, it's not always off by that exact percentage...but it's close. This only happens for taxed items so I assume it's releated.

 

Can someone PLEASE give me an idea of what it could be or where to look/start?

 

Thanks a lot!

 

Joe