I know this doesn't help, but I'm seeing no change printing to the 7900 or 11880 using Snow Leopard, either with LR or Photoshop.
Are you using the 16 bit option in the printer driver? Do you have snow leopard starting up in 64 bit mode? Is Lightroom running in 32 bit or 64 bit? No clue if these things would make a difference but it seems some of the issues users are having with SL seem to be related to some of these settings.
Do you have the same problem printing from Photoshop or just LR?