I took a look at the driver download page you posted.
I think you are right and they are a copy of the same drivers already mentioned before.
For some people, Catalyst 8-3 for Windows XP work just fine on their HD2xxx agp card.
For others, not.
Same story for the Linux drivers.
There seem to be too many variables involved (motherboard chipset, motherboard RAM, 64-bit or 32-bit, Intel or AMD) for a consistent picture to emerge.
The writing on the wall that says "you're on your own with this one for now" is the fact that AMD/ATI have still not anounced official Windows XP, Vista or Linux (32-bit or 64-bit) support for the HD2xxx series AGP cards
Until that wonderful day comes, your mileage may vary.
In my own case, my 2600xt 512 MB AGP works flawlessly in XP 32-bit with the Catalyst 8-3 driver package, yet refuses to do anything usefull in Linux unless I turn all Direct rendering (and therefore, accelleration) off.
I'm on the open-source radeonhd driver in Linux which still has it's own problems (xrandr not working in the 1600x1200 resolution that I want on my two monitors despite preallocating a massive virtual of 3200x2400 for it. So RandR is off for now.)