Apple Logic Pro /LogicExpress Discussion

Hey Gang, 

This is both a quasi survey, and a quest for tech help.

I started a re-mix project yesterday.  My friend Rachel Loy let me have a copy of her Pro 
Tools TDM session for my audio students to try mixing.   I was able to truncate her 50 
tracks down to the 32 required for Pro Tools LE.

I decided to try mixing the session myself in order to practice mixing.

When I pulled the files into Logic to start mixing .... it just wouldn't play!!  Maybe a 
measure and then a window pops up and says "sorry charlie" so to speak.

I've tried all kinds of things with buffer size, with putting the project on external firewire 
drive (through a hub), or internal drive.

When I open up the project in Pro Tools on the same computer (G5 Macbook) it plays fine, 
and I can insert plugins without any complaints from the CPU.

I'm tempted, in Logic, to add tracks one by one and see when the computer finally 
surrenders.

I'll have to resort to doing sub-mixes of drums, etc. in order to mix this.   But wanted to 
see if any solutions other than Ensemble or somthing were discovered among my Logic 
Pro peers.

Thanks for any input on these matters!