8.45 refers to the driver version while 8.1 is the package version (Catalyst) including control software and so on.
I have found driver 8.41 is sadly the only viable option -for AGP on XP, at least. The next release gibbled 3D and the next two including current 8.45 are incapable of DxVA on a secondary display. Full-screen mirroring by VMR7 Windowed still works but if the player must be on the secondary to show there (as with BD/HD DVD) then DxVA is inactive. Scuttlebutt is that Catalyst 8.2 (driver 8.46?) is due shortly (perhaps this week) so I hope this defect is corrected.
Otherwise, the 2600 Pro is ideal for motion video and not too shabby for light gaming although the XT would be a better choice in that regard. The fan runs too fast by default so needs third-party software or some DIY hardware fix, in my opine.