Must admit when I installed this software, it took a long time to get all the settings correct, but when I did, I had no problems whatsoever.
Double check correct model mouse config, because with this software it caters for many models, then check battery power status.
Try bypassing the Belkin switch and plug straight into the dell, could be that the m/soft drivers do not like sharing with other devices such as the Belkin KVM switch.
If your other computers are XP Try it out on them.(just to isolate the problem)
bretsky using win xp home ed sp1 on a Dell dimension 4300 with 1 Gb sdram,P4 1.8GHz processor, 180Gb 2xHDD Nvidia GEForce graphics, Nav 2002, m/s wireless optical mouse 2.0 + wireless multlmedia keyboard 1.0A with Intellipoint 5.0 driver software.