RAM Issues

I have recently purchased new RAM and are having the following issue, this gets intense.
First: RAM Specs..
--Old RAM
512mb PC3200 DDR SDRAM 400Mhz
2 sticks

--New RAM
1g PC3200 DDR (doesnt state SDRAM) 400Mhz
2 sticks

Second: Problems
With both new sticks plugged in -- Computer loads up until right before Windows XP begins to load, then it auto-reboots

With 'Stick1' plugged in (only 1 stick, in slot 2 of 2) -- Computer loads effectively up until I log in under my username. Background loads then it auto-reboots. In Safe-mode, I can effectively log in as Administrator, then soon as I run a program, system auto-reboot.

With 'Stick1' plugged in ( in slot 1 of 2 ) -- computer gets done with the initial XP loading screen, then freezes, does not auto reboot. Keyboard and Moniter stop working.

----------------------End--------------------------
I really have no clue as to why the RAM will not work, as such the RAM specs were identical (from what I have been given)

 

This is the specifics for my motherboard..
http://h10025.www1.hp.com/ewfrf/wc/...657&lc=en&cc=us&dlc=en&product=501666&lang=en

This is the link to the RAM (purchased off Ebay)
http://cgi.ebay.com/2GB-PC3200-400M...yZ138342QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

Thought that could help.

 

Another addition.. this might be the problem.. but not sure..

The RAM I bought is Dual Channel, and my motherboard does not support Dual Channel..

 

try clearing the cmos . The old timings may be stuck there and if the timings are different on the new ram it may cause issues

 

What is cmos used for/what does it do? Just like to expand my knowledge

 

Didn't work. Same issue with booting after installing the RAM.

 

I've been told that the purchased memory is 'high density', although I doubt this is a reliable response based that I had no clue there was density to RAM. Can anyone reply as to what RAM density really is?