Time Delay between Clicking Track List and appearing in midi Editor

[Jeanpaul]

I noticed a weird thing with PT 9.03, Win7 64 Pro. When I am in the Midi Editor and I click to show a track from the track list, it does not appear immediately but takes a fraction of a second for it to show up. Also, when I click to hide a track that is showing, there is delay between the click and the actual disappearance of the track from the midi editor.
If I fast click on several tracks continuously it take a few seconds for them to appear, and I can't click on anything else until they do appear. If i click on several tracks from the track list and start editing stuff before they appear, the whole Win7 system freezes in most instances, Ctr+Alt+Del task manager would not work, and I have to maunally switch the power off and re-boot.

UPDATE: I tried it with another session that has 4 midi tracks only and very few plugins, and the problem disappears. The tracks show instantaneously! So what could the problem be when i have more tracks?

What could be the problem? Is it related to my graphics card? I have a Nvidia Quadro 2000 (1GB), and have installed the latest drivers (275.61 WHQL certified driver). I reverted to the 259.81 driver that is recommended by Avid for Pro Tools, but the same problem is there!
The session I am working on takes about 4 GB of my Ram, with around 10 instances of Kontakt 4 and a few other plugins. The session has around 90 midi tracks.

I am on a HP Z600 workstation, with 2 nos Xeon 5620, 8-core, 2.4 Mgz, 16 GB Ram. No Hyperthreading, No Intel Turbo Boost. 5 Cores are allocated to RTAS with 99% CPU usage and the buffer is 1024.
Any suggestions?
Any help is much appreciated
thanks

[Jeanpaul]

Bump ! help is appreacited. This delay really slows my workflow.

[Jeanpaul]

Bump ! any ideas anyone?

[Jeanpaul]

Suggestions anyone ?? Bump

[filosofem]

You might have maxed your system, when was the last time you did a fresh install of Windows on a new partition or starting back from a clone? Pro Tools likes it lean and mean.

[yoerik]

Hi Jeanpaul, happens to me too in the edit and mix view. right-clicking and selecting (show/hide) is (a bit) faster. Fastest (on my system) is selecting all tracks I want to show/hide, then right click and select show/hide. Trying to do this by clicking the track show/hide icons one by one in a 100+ tracks session is quite annoying indeed, even if cpu load is low.