Yes, my apologies for the brevity of my initial question - this was from Design Checker. As Hilary stated, I located the offending view by systematically eliminating items/views until only the offender remained (along with the error). I then created another form without the offending view and systematically copied over parts of the table and then performed Design checker. Oddly enough, after copying over every part of the table a piece at a time, the new form did not have the CSS error, so I apologize, but I cannot offer any insight as to exactly what caused it.
One thing I do need to keep in mind though is that in addition to performing Design Checker after each revision session, I also Preview the form. One time I saved the form and only performed Design Checker and then when I went to Preview it, InfoPath told me there was a catastrophic error - Too Bad Sucka (DAP paraphrased). I don't know why because Design Checker told me everything was copasetic, but that copy of the design file was no longer viable.