Frame rate conversion, judder and Timewarp crashing

I know I know, Frame rate questions asked all the time. But search did not yeild the right question asked nor an answer i need. So apologies if this is all over the Cow and I missed it.

I have been given 29.97 footage to edit into an already built AE show at 1280x720 24fps.

I have tried various methods of converting the footage to 24fps and all results in terrible judder at certain times. I tried adding RSMB and that helped alot, but there is a noticeable "2 clean frames 1 blurred frame" pattern I can never get rid of. Obviously the actual frame rate conversion is not clean enough, an no amount of motion blur is going to help it.

I came across Andrew Kramers frame rate tutorial and have been trying to apply the timewarp plugin as he suggests. However, this just locks up AE and I have to force quit. WTF!

I am on a MacPro 8-core, 6GB RAM, ATI 3750 GPU, AE CS3. This system should be able to handle this.

Any ideas, I'm stumped and the client is getting antsy
cheers
mm66

Adam Mercado
Influxx Media Production
Motion Graphics & Video Post Production
Fullerton, CA