Hi agian, So that rename the folder don´t work on Mac, hmm, then i don´t know.
The floater error u get is after AS2 is uninstalled, i got that too on my Windows 7, After i uninstalled Form Builder and then AS2, but the error sorted it self out after i reinstalled AS2 with out Form builder installed.
Do a search on the Configfolder for mac, in windows the Configuration folder is in
And DW recreate the Configfolder if if finding its missing.
I found this for you, As it looks Do Not Rename the Configuration folder that is in the Application folder on your Mac, it should be in your Profil folder.
ex. Mac OS X: Macintosh HD:<username>:Library:Application Support:Adobe:Dreamweaver CS4:<language>:Configuration
Heres a link: 417116
Hope this helps