I've fixed my freezing problem on bootup with backtrack2 live CD!
Try this command at the boot prompt when booting from CD

bt acpi= off

This worked for me my live cd boots into backtrack2 now
auhhh....don't know what the command means, maybe someone can explain??
but I'm a happy camper now!!

This was where CD was hanging on bootup and I know a few others had same problem in that area at bootup.

pcmcia: parent PCI bridge I/O window: 0xa000 - 0xafff
cs: IO port probe 0xa000-0xafff: clean.
pcmcia: parent PCI bridge Memory window: 0xc0200000 - 0xc02fffff
pcmcia: parent PCI bridge Memory window: 0x40000000 - 0x43ffffff
shpchp: Standard Hot Plug PCI Controller Driver version: 0.4
cs: IO port probe 0xc00-0xcff: excluding 0xc00-0xc07 0xc10-0xc17 0xc50-0xc57 0xc68-0xc6f 0xcd0-0xcdf
cs: IO port probe 0x820-0x8ff: excluding 0x878-0x87f
cs: IO port probe 0x3e0-0x4ff:
(point where it hangs)

on to higher learning.....