Very Poor Macbook Performance

[StockDC2]

Hi, I just purchased a Macbook Unibody with the following specs:

Core 2 Duo 2.26Ghz
2GB DDR3
250GB Hard Drive

Right off the bat, I am having multiple problems. One is that there is bleeding right above the bezel where it looks like individual LEDs are shining through 8 or 9 openings. Another problem is that the computer is slow. Hell, even the mouse cursor is choppy when moving it around on desktop.

I did a reinstall of the OS but the problem is still there. Any ideas on what it can be? Btw, I also swapped the hard drive with the one from my MBP and there is still laggy performance.

 

[StockDC2]

Odd... The sluggish performance is attributed to whether or not the computer is plugged in. If it is running on just the battery itself, it runs terribly. If it is plugged into the wall, it runs perfectly.

Is there a way to adjust the settings so that the CPU doesn't get throttled when on battery? I know that there was an option on regular Leopard but I don't see it on Snow Leopard. Does Lion have this option?