Known issue (and solution) with ASP Server Validation
We have discovered a known issue with Validation Toolkit 2. When using Server validation in ASP, a querystring variable added to the failed validation URL will not be passed correctly if validation fails a *second* time. Replacing two files will resolve this issue if you are experiencing it.
To get the fix, log in and visit downloadcenter.php. Click on Validation Toolkit 2; then click on the Known Issues section. Download the zip file and follow the instructions in the readme file.