Using the latest version of Adobe Flash 11.3 on either Internet Explorer or Firefox, and attempting to play this game: http://www.freeonlinegames.com/game/park-master causes the game and the browser to become unresponsive. Reverting to Adobe Flash 11.2 does not cause this issue.
Thanks for the heads up. While I didn't have any problems with IE, Firefox would load the game but the browser became unresponsive once starting up. I've forwarded this to the team working on these issues. In the meantime, would you mind opening a bug report at bugbase.adobe.com so we don't loose track of this and you can get updates? If you post back with the bug number or URL, I'd encourage anyone else that can repro to add their votes and comments.