Forms: Erroneous Messages

Hello,

I am receiving erronneous e-mail messages from two of the submission forms
on my site. In both cases, either the number 48430 or 32127 is what is
being entered into the entry field.

I am receiving these messages pretty much on the hour, and have been for the
last few weeks. The forms otherwise still work for legitimate use.

Any ideas on what the heck this is?

-Jeff