Hey all,
Just adding my two cents here, that i too am having the same issue.
I started with a clean prefs file. No problems.
I arranged my pallets the way I like them. No Problems.
I opened the Pantone solid coated, set the window to "persistent". Still No problem.
THEN I opened the preferences within Illus un-checked the "Font Preview size" and NOW I had a problem.

So basically to recap. If you set the pantone pallete to "Persistent" AND uncheck the "Font preview size" - this will somehow corrupt the pref file, so that upon restarting Illus CS it will "unexpectantly quit".

Hope there is a fix for this soon.
Cyen