You don't need to install Warp3D, the OS already had 3D hardware support built in.
Suggest you do a fresh install of OS4.1, update 2-3 I found to be the must compatible with 3D games, after that some stuff seems to have been broken but at least Quake II, Wipeout2097 and Open QuakeIII Arena all work great on update 6 with my uA1.
I really had to go with update 4+ since it fixed a nasty networking issue.
I never got Payback to work on 4.1 properly, it's for OS3.x and like a lot of 3.x stuff does not work 100% with 4.1