Protools Conflicting With Tiger, On a 17" Powerbook Options

[newgroove]

I'm running one of the latest 17' Powerbooks and had to recently install protools 6.9.2 which was sent to me after 6.4 wasn't running under tiger. The problem changes severity between two issues, sometimes protools won't play or record for longer than a second without coming up with any one of these messages

-Audio processing is conflicting with other CPU tasks. If this occurs often, reducing the H/W Buffer Size in the playback engine dialog may help provent the problem. (-9129)
CPU usage is holding off USB audio. Remove some plug-ins delete some tracks, or increase the "H/W Buffer Size" in the Playback Engine dialog. (-9136)

thats the worst case scenario, other times (and this is the confusing one) is when protools will work perfectly by itself until i try to access the dock or apple-tab into another program, then protools will bring up the same errors i mentioned before.

I have searched high and low over the net for an answer but can't find anything that works. I've tried administrator privledges, turning off bluetooth and airport, energy settings, buffer size.... seemingly everything

the only hint i can give is that i found a previous copy of 6.4 that i thought i had deleted which i thought may have somehow been screwing around with the preferences but i have since uninstalled both that and 6.9.2 and then re-installed 6.9.2

any help would be muchly appreciated.
ta
newgroove