I'm been trying with several distros, and it appears that the only one that works on my hardware is ideneb 10.5.7. After booting off the dvd, i get to the point where I have to select which partition to use. Here is my problem, I currently have a triple boot system

a) xp
b) windows 7
c) gentoo

They all have their own hard drive. I'm trying to install mac on the same drive where windows 7 is. The problem is that the drive where windows 7 is already has two partitions created by windows and the mac installer does not let me create a separate partition on the free space. I have to select paritition scheme and it doesnt make sense to me. To me it would be simple if i can just select the free space, create a new partition and formatted the drive, but i cant. instead, i have to select from 1 partition to 4 partition or whatever i want which is confusing. I want to keep my two existing parititions and create a third one. Am I missing something?

I will be using grub to boot mac, any advise you can provide on what to do to successfully add mac to grub is greatly appreciated.

There are a couple of issues here.

First, you must have free space on the drive to create a new partition. In this context, "free space" means space that's not currently allocated to partitions; you could have hundreds of gigabytes of free space available within a partition and it would be useless for installing a new OS. If you don't have unpartitioned space, you'll need to use a partition resizing tool (such as GNU Parted or one of its GUI variants) to resize and/or move your partition(s). A caution: Windows tends to be fussy about its boot partition. If you resize your Windows boot partition, it might stop booting. Test and, if necessary, repair it before you proceed.

Second, the OS X Disk Utility is rather inflexible and confusing in some respects. I recommend you create a partition in another utility. If possible, use that utility to create a partition of type 0xAF (the type code for HFS/HFS+) and/or create an HFS+ filesystem on the partition when you create it. If your partitioner doesn't support this, then try to make it FAT (type 0x0C); Apple's Disk Utility will probably let you reformat that for HFS+.

thanks for your suggestion. I was thinking along the same lines of creating a fat32 partition and then telling diskutility to format it for apple. Just to clarifiy, i do have a little over 630GB of unformatted space. My issue is that when it's time to select the volume scheme, if I leave my current scheme, which is basically my two window 7 partitions and the unallocated space, diskutility cant do anything with the unallocated space as it's grayed out. However, If I select per say 3 partitions, the unallocated space is no longer grayed out and I can go ahead and format it. I dont feel comfortable doing that, as it simply divides the entire drive into three partitions completely ignoring the existing partitions and their size which are 200MB & 350GB respectively.