I just uninstalled windows from my bootcamp and i would like to run only my Lion and a second partition with BackTrack 5, is it doable?

I already tried to follow a couple tutorials i found around here and there, and all of them asked to partition my mac with bootcamp and then instal rEFIt, but this isn't possible on LION since when i try to partition my HD it asks for a Windows Installation disk..

What i did until now is, partitioned with disk utility my HD with success and now i have two partitions with around 250gb each, the one i'm using for mac is in HFS+ as usual and the other in FAT but it's empty.
I managed to install rEFIt too and i can boot on it with no problem.

I Burned a CD with the new backtrack 5rc1 iso GNOME and i can't seen to boot from it, when i boot on rEFIt it gives me two main choices, that is to boot on the OSX LION or in the "Legacy OS from HD" which i tried to choose and i just have to reboot my mac to boot on mac again, since nothing happens.

My main config is:
MacBookPro5,2 (17-inch, Mid 2009)
Processor 2.8 GHz Intel Core 2 Duo
Memory 4 GB 1067 MHz DDR3
Graphics NVIDIA GeForce 9600M GT 512 MB
Software Mac OS X Lion 10.7.2 (11C74)

Well, any thoughts on that, because i really would like to run Backtrack native on my mac because i don't have any flash-drive?

Thanks in advance