Basic System Requirements for running 3rd party samples

Question

Here's a VSL instruments conundrum.
From what I can see, I've got approximately double the minimum system requirements spelled out by VSL for running Vienna Instruments II. But my system is crashing immediately with only one instrument plugged in.
Here's my full setup and things I've tried so far.
MacBook Pro, 1.86gHZ Dual Core processor, 2G DRAM.
MOTU Ultralite I/O Interface
Logic Pro 7.2.4
500Gig 7200 RPM, 8mb cache RAM external Western Digital Hard Drive.
Firewire 400 (the early MacBook Pros from last year didn't have 800).
VSL installer, Logic Pro, and Syncrosoft are the latest updated versions (just bought VSL last week).
Vienna Instruments are installed on the external. Logic Pro and Vienna standalone are installed on the internal computer drive (200G, 40G empty).
Since I only have one firewire slot, I have tried piggy backing the MOTU and the 500G external hard drive both ways (MOTU plugged directly into the computer in front of the HD, with the HD piggy-backed into the MOTU's firewire slot, and the HD in front of the MOTU). No difference in results.
Specific issue: everything works flawlessly until I plug in just one Vienna sample. As soon as I choose it (before playing anything), the system starts to crackle, and even just trying to audition the sample in the AU Standalone taxes the system beyond being able to make a consistent sound. As I touch the "piano keys" in the standalone, most of the time I get no sound, other times I'll get the note accompanied by a lot of crackling. Then when I actually try to play the sample in a Logic Pro track, all sound is hosed. Only solution is to reboot Logic Pro, and 1/3 of the time I have to reboot the computer itself.
This happens whether I have 10 other Logic Pro instruments plugged in or none. One highly optimized Vienna sample by itself hoses the whole system (example - I've tried the Bosendorder optimized to only take up 1MB of RAM - same result including only 20% of the notes playing in the VSL standalone before I even try to play it in a Logic Pro track).
The system requirements spelled out by VSL are about half of what my system has. (VSL calls for a minimum 1G processor and 1G of RAM - I have a 186gHZ Dual Core processor and 2G Ram). I don't mind having to optimize and play some tricks to get 6-10 instruments to play at once, but I can't get a single instrument to run (with double the minimum system requirements).
Spent 2 1/2 full days working on this so far with no progress. Any suggestions? Thanks in advance for your help.

Answer 1

Well, you've managed to start three separate threads about the same thing. This not only fragments all the responses you'll get, but it also limits the search engine for future users experiencing similar problems, looking for solutions.... but hey, it ain't my forum...
I can't help but wonder if having two FW devices on the same bus is causing a bottleneck on the FW buss. Getting an external FW card for your mac might be necessary...keeping the VSL Hard Drive and the MOTU interface on separate busses.
In the meantime, try this... switch your audio driver to "Built-In Audio", so that Logic is using it's internal sound card, not your MOTU. Try loading a VSL instance and playing.
If it works, playing through your computer's speakers, then you've possibly found the trouble.
Have you emailed VSL Tech support yet?