This CPU should work right?

No. P4 650 was the end of the line for that beast.

Hmm I must be missing something

It's got the same socket and FSB , is there something else in the specs I need to look for for compatibility?

Not really. That's just the way it is with s775. There were so many chipsets. Unfortunately the i915 in your motherboard does not accept any core 2 duo's or wolfdale dual cores because they were 65nm and 45nm. The i915 was for Pentium 4's at 90nm. Some s775 boards accept 90nm cpu's, but not 65nm cpu's, Some accept 65nm cpu's but don't accept 45nm cpu's.

Your board was made for 90nm cpu's, that cpu you linked is 45nm. Two generations newer.