RTAS Meter Creeping up when stopped

[BrownMan]

Hello,
I am using a dual G5 2.0 with 4 gig ram, OS X 10.4.11 and LE 7.4 (latest).
I have a project with 12 tracks. No effects yet except on two tracks. One track has Eleven the other Waves GTR3. I also have one Aux with a Dverb.
When I play the tune the RTAS meter goes down to about 10-15% usage. When I stop, the meter climbs up and holds at 75-80%.
What is very weird, I have a version of this tune with UAD-1 plugs on every channel including the original Eleven & Waves plugin. The RTAS meter is steady through out the song (about 15%). Doesn't matter if stopped or playing.
Any ideas?
Regards,
Rich

[BRH]

Well, ..idea? Waves recently updated their "Waveshells" if you haven't done this, maybe it would help.
I don't know how the the GT3 works, but guessing hardware plus plugins. I'm on 7.4 and OS 10.4.11 and all runs freely.