I have installed CS4. Not aware of anything I did to enable Adobe Gamma. Don't see it as a start up item in Windows Defender. Anywhere else I should check to make sure it isn't enabled/starting up?
I don't know if CS4 installs Adobe Gamma loader as a default. I'm still on XP SP3 so I don't know Vista. Can you still run MSCONFIG? If it's installed, Adobe Gamma loader will appear in the "startup" tab. Check it "off" and reboot.
Also, as I'm sure you're aware, with a wide gamut LCD like the 2690 some colors will appear overly saturated in NON-color managed apps. For example, you'll want to use Firefox 3 browser with color management enabled (there's an add-on that does this easily)