Quake2: low end graphics cards (GeForce2 equivalent or lower): use D3D6 plugin if D3D8 shows major errors.
Quake2: slowdown on explosions (worse on some systems?), no fix.
Quake2: title screen background blue, should be black. no fix.
Quake1: multiplayer unusable, graphics errors for all players. no fix.
Quake2: multiplayer with 3+ players unusable (graphics issues in screens 2, 3 & 4 - getting more severe from 2 to 4). no fix. 2 players OK on internal pipeline (use D3D transformation pipeline disabled).