Why does my new Hard Drive cause system shutdown

I have an early 2006 A1150, with 2 GB of RAM.

I had just installed a new HDD (http://www.newegg.com/Product/Product.as...) which is a Seagate 7200 RPM 500 GB drive. Which I've researched others successfully installing into their laptops.

Now the box will shutdown after an intermittent amount of time. I gain the most of the time, when the box has been turned off over night and is stone cold.

Does anyone know what the problem is, am I drawing too much power?

Is it too much heat?

Is the extra power causing something else to overheat?

Does the Logic board not support 7200 RPM or some other protocol? (S.M.A.R.T/ Sata 3 / etc. )?

Is some kind of firmware required?

Should I get a different brand (Western Digital) or different speed (5400 vs 7200)

I was running the latest patched version of SL w/Vista SP2 via BootCamp. I didn't have any problem installing the OS, it just seems like this started happening in the last week or so.

If you want the full story click over here.(http://www.ifixit.com/Discuss/thread/969...)

Thanks for any ideas or help. I will keep everyone posted on my travails.