Help! CS2 Ai, Psd, ImageR and InD crash on open.

Question

I have been happily running Creative Suite 2 Premium on my iMac Intel Dual Core with OS 10.4.11.for 18 months.
Suddenly each of the major apps crashes on open with dialogue:
EXC_BAD_ACCESS (0x0001)
KERN_PROTECTION_FAILURE (0x0002) at 0x00000000
I Have:
1. Cleaned and rechecked all OSX Fonts and Adobe Fonts with Font Doctor 7.6.0. Purged Font Caches and ensured Font Agent Pro 3.3.2 is switched off at start-up. I earlier resolved any Helvetica or Times conflicts.
2. Run fsck -fy and Permissions.
3. Trashed all CS2 app folders and re-installed all apps and up-dated all apps. Still the four apps crash. Can there be old preference files causing the problem?
I cannot figure out what has changed to cause the problem.
Internet references have identified update OSX 2004.11 Security Updates 2008-002 caused this problem but surely we are beyond that now.
Adobe Archive only identifies this dialogue with problems opening Quark files in InDesign so is of no help.
I would be most grateful if anyone can pinpoint the source of this problem as my work has stopped dead.

Answer 1

Thanks Eric,
Holding down cmd-opt-shift-control had no effect. (No dialogue 
opened, just the usual EXC_BAD_ACCESS)
Tried Onyx, thank you for introducing me to a useful set of tools. I 
used Cocktail previously for maintenance but this set offers more 
alternatives.
Fact is on restart nothing has changed. I have bee racking my brains, 
(a 60 second exercise) to try and remember what actions may have led 
to this change in circumstance. Nothing comes to mind.
While acknowledging the validity of Buko’s comments, I would like to 
say that originally I found no problems running CS2 in 10.4.11. I am 
sure it would be slower in emulation but forking out another $1,000 
for an upgrade is not attractive, and CS4 will have another set of 
problems?
Fortunately I have a souped up G4 (1.8 GHz 7447A chip), onto which 
which I can load CS2 and working files.
I shall strip out all CS2 from the iMac and remove all non Apple 
fonts then re-install again.
If anyone has any further ideas I will appreciate your views. How 
many others have met with this issue?