How can I debug the following issue:

I have my e-commerce application, based on TBH, working just fine in a production environment.
After some time improving the application I tried to add an item to the ShoppingCart and got the following error:

System.FormatException was unhandled by user code
Message="Especificador de formato inválido."
Source="mscorlib"

When I test the application in the old CPU with the same win xp / vs 2005 it works fine.

I identified that the problem is with the controls state and SetInputControlsHighlight method when using the new CPU. If I isolate the SetInputControlsHighlight method I don't get the error.

Can anyone give a direction to solve this problem?