vqregister errors

[Lanny Baron]

Hello,
Using vqregister on one of my domains, constantly produces an error when 
people try to subscribe to it. The message is:
Unrecoverable Error: Internal field check error.

An unrecoverable error occured while processing your request.
Please contact the administrator if this continues.

vQregister v2.5


But the person does get registered. Any one know what the problem is and 
how to fix it?
Thanks,
Lanny