Well... i can't open CS4 either now...
Your hang report shows InDesign getting stuck in the flash player.
Cna you please try with a brand new user account?
Did you trash your preferences?
Just tried with another user account... it works fine...
It happens. Try removing the folllowing Library directories:
Library/Application Support/Adobe/Adobe InDesign CS5.5
Library/Saved Application State/com.adobe.InDesign.savedState
From your User ~/Library directory.
Tried removing, tried removing flash directories, tried reinstalling Flash... nothing...
Tried reinstalling InDesign... didn't work either... i'm close to switching to the new account i created which would set me back in other areas.
Mikkel, if the problem goes away with a new account, it is almost certainly a problem with your ~/Library folder, and reinstalling InDesign does not touch that, so it is no surprise the reinstall did not help.
If you truly removed all the folders I specified, then I'm quite surprised it didn't fix it. Sometimes it is a permissions problem -- you
might check the permissions on those folders with Get Info in the Finder, and maaaaaaaybe try running Disk Utility's Repair Permissions (usually a waste of time).
If not, well, try moving *everything* out of your Library/ folder, and then putting it back bit-by-bit (well, half-by-half). This may be a somewhat unpleasant and potentially destructive process.