Thank you! That wasn't actually the problem, but it led me right to the problem :) The default device ID is 101 (don't know why, Microchip just makes 'em that way), but the device code was not 1010! There's an ambiguity in the datasheet; it says in the text that it's 1010, but all the diagrams show 1001 - so, I tried it that way and it worked perfectly :) I then emailed Microchip in the hopes that they would fix the typo ASAP to avoid future confusion :)
Thanks for the assistance, much appreciated!