Well, the verdict is in, and indeed, it is the drill bit. After reading everyone's replies last night, I took a look at it this morning, and it was about as sharp as a sack of wet mice. (Thank you, Foghorn Leghorn.)
But...the saga continues...
I only found one supplier in town that sold individual sizes, and it happened to be the Austrian bits sold by Delta. Wonderful!! Looked like good quality, made (packaged?) by Delta...gotta fit my mortiser...which conveniently is a Delta too.
Wrong. Being made in Austria, the "chuck" for the chisel is 16mm. The chuck for my mortiser...5/8". It was then that I noticed the tiny label on the box, "For the Delta drill-press mortising attachment." What it should have said was "For the f&cking drill-press mortising attachment," but I digress.
So I sits and I thinks...hmmm...if I can't take 5/1000's of an inch off a round piece of steel with some emory paper...I'm pretty much shit worthless. Then I looked at my original chisel, and my new bit, and it hit me like an old Reese's peanut butter commercial. ("You dipped your...")
Wala...new bit/old chisel goes through cherry like crap through a goose.
BUT I'M NOT DONE YET...OH HELL NO!!
Unfortunately, the new bit is .38 inches wide...my old chisel is .36 inches wide. Enough to leave every "plunge" with a big round groove in the side. Not what I'm looking for in a mortise. And the new chisel is almost as bad, so even if I did make it fit in the chuck, it's still proud of the chisel by a long shot.
So now, I just have to order a new one from Lee Valley, and all is well.
Except Lee Valley is backordered on 3/8" for two &^%damm months. &^%$#@%$&%#&%!!