Something similar happens to me too, although my mouse does not move in reverse. I found a temporary fix and that was to boot into windows side and then reboot back into leopard. Don't ask me why it works, it just does for some odd reason.

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MOBO: Nvidia nForce 590 CHIPSET: nForce 590 SLI
RAM: 2 GB (specifics unknown atm) CPU: AMD Athlon(tm) 64 X2 Dual Core Processor 5400+ 2.80 Ghz
GPU: EVGA GeForce GTX 260 896MB 448-bit GDDR3 -- 192 cores
HDD: Hitachi HDT725032VLA SCSI 320GB - SATA; Maxtor 6L200R0 ATA 200GB - SATA
WLAN: Gigabyte GN-WP01GS PCI WLAN Card(Turbo) -- Currently Uninstalled
LAN: NVIDIA nForce Networking Controller
OS: Snow Leopard 10.6.1-10.6.2 Intel AMD made by Hazard; Windows Vista Home Premium 32-bit