On Mac OS 10.6 (Snow Leopard), I was having the same problem described by many in various discussions on these forums.
At my company, we have found that, beginning with CS3, the Adobe Updater very often will not run (or rather will launch and immediately quit) if run under any user other than the first user created on the Mac (in spite of the fact that all users on the machines are Admin users). To get around this problem, we run the updater from Terminal with Sudo or as the user known to have been the first one created (that one is always assigned the UID 501).
Having remembered that, I tried running the Flash Catalyst installer as the user who was first created on my MacBook Pro. The installer ran very quickly and completely. Once installed, I can log in as any other user and run the application without any problem.
Please, Adobe, find out what's going wrong with your Mac installers and updaters that's looking for that 501 user and fix it. You'll save everyone days of troubleshooting and save yourself a lot of frustrated users and system admins.