So, after some reading about why my N900 didn't detect my headset as a headset I opened it up and indeed, it was just as they said. The white M+ lead is torn off the solder. I didn't open the headset up until after I had my entire N900 torn apart on my lunch break. At least I got a shitload of dust and pocket lint out of it.
I now have tools to try to fix this thing.
So, I had 3 minutes left before leaving for the station and soldered the mofo back together and the headset now works!
Update: 2011-10-20: Soldering broke and cable came loose while on my trip to the States, so I resoldered it again today at the office.