Hi Chris,

Yeah, it does seem odd unlikely that if it was bent, it'd be so evenly distributed both sides.

As Timster says, you need to get it to some one with decent 4 wheel alignment equipment, and a really good operator so he knows how to use it properly.
Do full check, with print outs so you can see what the score is.
Run out on the wheels then camber, toe and caster (for the front).
Knowing the cars foot print will help you diagnose it no end.
Let us know how you get on.

Justin