Tried running the apps on a brand new user account… same deal.
Just updated from 10.5.5 to 10.5.6 same deal… It never actually crashes until your patience runs out and you ‘Force Quit’ the application. So then CS4 came out… installed the trial… it actually loads (during the splash screen anyway) but once you get to the ‘layout’ page, it shows the tools, panels etc but if you hover over any of them you get the magical "beach ball" for eternity. So I thought perhaps I should try a newer version of Photoshop, so I downloaded the CS3 trial… also crashes. Macromedia Flash 8 simply crashes on startup, no further info. Photoshop CS would yield errors that referenced ‘CarbonLib’ in the error message.
Over time, I forget exactly when, Photoshop and Flash applications crash when attempting to start them.