Sometimes while debugging I get the following error (see in attachment)
The only issue I found was to replace in the eclipse folder the FlashPlayer.exe by the Debug version downloaded from adobe, and it works after that. But the error comes again and I have to repeat the operation.
I'm on Vista 64.
Just reported the bug but if there is any others issues let me know :-)
Have you tried to configure Preferences->Web Browser window to specify the debugger browser you downloaded or installed? select "Use external Web Browser" and choose the one pointed to what you downloaded, give it a try as work around?