MDB2 Error: constraint violation

Hi I'm using the MDB2 library with PEAR and I get this error sometimes when I try to submit a form on my website:

MDB2 Error: constraint violation

The page is completely blank with only those words in the top right. The form submits information to a PHP script which checks the info and then inserts it into a database. Any idea why this is happening or how to fix it?

Thanks,
Marc

Oops, fixed it. I had a unique parameter on a field in my database that shouldn't have been there.