I opened an image file with FireWorks CS4 by mistake, and I thought it would go to crash. But, it showed the activation dialog and could quit the application safely after opening the file.
Then I tried to check FW CS4 as main editor in DW CS4. Anyway though, there are still many possibility of sudden crash.

DreamWeaver CS4 almost runs well on my works.
I usually use dual display (display of MacBook Pro and an external display). I sometimes bring out MacBook Pro to other work place, and when I plug a different external display (different resolution), DW CS4 forgets the work place I registered. It messes up palettes.
I hope this bug will be fixed in next beta version.