Good work, Hoefie.
So others know, you can remove the letter form the 100mb System Reserved partition if necessary. Win7 should then assume C:
You can also remove the 100mb partition and recover the MBR into WIn7 partition by marking it active and running Startup Repair from Win7 DVD or Repair CD up to 3 separate times with reboots to force MBR move.
To avoid having 100mb Sys Reserved boot partition assigned at install, pre-partition the HD. It's only needed for Bitlocker encryption in Ultimate or if you want the Repair Console added to the F8 Advanced Boot tools which to me is it's only plus.