All - I'd like to report back. I'm sitting here at the gate at OKC (after security). Having just gone through security with my colleague for the return trip - I can report that we had no issues at all. Turns out that TSA didn't even question the boarding pass/I.D. at all. On a side note, my colleague's drivers liscense didn't even have his full middle name - just the middle initial (he did bring his birth certificate and SS card just in case there was an issue). I have to admit that I'm a little surprised that he wasn't even asked a question or two... Not that I'm complaining since it all worked out.