I can confirm that with 6-STABLE (built on June 1st, 2007). Driver 9746 exhibits out-of-sync (according to my monitor) problems on the console once X has run at least one time. Before X has run, there are no apparent problems. 9631 does not exhibit the same problem.
1. Running nVidia AGP.
2. BFG 6800 OC AGP 128MB
4. dmesg (verbose) boot:
nvidia0: <GeForce 6800> mem 0xfc000000-0xfcffffff,0xb0000000-0xb7ffffff,0xfd0000
00-0xfdffffff irq 16 at device 0.0 on pci1
nvidia0: Reserved 0x1000000 bytes for rid 0x10 type 3 at 0xfc000000
nvidia0: Reserved 0x8000000 bytes for rid 0x14 type 3 at 0xb0000000
nvidia0: Reserved 0x1000000 bytes for rid 0x18 type 3 at 0xfd000000
ioapic0: routing intpin 16 (PCI IRQ 16) to vector 49