Originally Posted by
plinko83
Same here, I gotten have my first name and entire middle name as one long name. Never had any problem with check-in, TSA, or skymile redemption.
More often than not I fly as 'LastFirstMiddleMr' thanks to my corporate travel agent. I still get my skymiles, and they even let me back in the country.
I suspect the OP's problem is simply that the SM number isn't on the DL PNR for some reason. This should be easy to fix, possibly even through DL.com.