Help! Cannot boot into windows, freezes at startup

I have been running OSX leopard on my 15" Macbook Pro 2.16GHz, have been using Bootcamp Windows XP once in a while and never had any problems with it. Three weeks ago I turned on my laptop and held the Option key to select my windows volume (as always) but the selection screen never appeared and freezes on the "white screen of death". I had to turn it off and on again to get back into osx.

I let it sit for several nights and tried again to boot into XP and it worked again. But the same problem showed up again few days after. I thought there's a problem with the Option key, so I went into OSX and set the default boot volume to the Windows partition, but once I restarted it freezes right away at the startup white screen.

I tried all the intel mac startup key combos possible to force it to boot back into OSX but none worked. I read somewhere that if I removed the battery and power cable and let it sit overnight it might work, so I did and used Command-Option-O-F or something and I was able to boot back into OSX to reset my default boot to the mac volume.

So then I tried to remove the bootcamp partition and install it again, the re-partitioning worked fine but once I was given the option to pop in the windows disc and press the "Start Installation" button, it restarts and freezes again on the startup white screen.

So I forced boot back into OSX and did a repair install and eventually a full clean install of Leopard, did all the Leopard updates and tried again with bootcamp. Still freezes at the startup white screen. I am stuck now, I guess its a hardware problem but OSX works perfectly fine. I don't know what else I can do, any ideas?