I promise you don't have to bump a thread after 12 hours, this was still in the top few threads in the active threads list.
Whether the cursor shows up or not depends on a number of factors.
1. The game you are playing (RIFT)
2. The version of Windows you are on
3. Whether Aero is enabled in Windows if it's Vista or later
4. Video card drivers (and possibly ATI/AMD vs NVIDIA. I have yet to see it "not work" with ATI, but have seen this with NVIDIA)
5. Whether the "Fake cursor" option is enabled in ISBoxer (it is enabled by default)
6. Whether Mouse Repeat has a cursor-based video feed enabled (it is disabled by default, and the fake cursor will not appear if enabled)
7. It could also depend on whether the game is set to Full Screen mode, or windowed mode.
It may be as simple as using an NVIDIA card and having Aero enabled. Or it might be from playing RIFT on Windows XP. Either way, try adjusting the various things above as appropriate/available.