[Moved from the defunct Getting Started forum into a product-specific support forum - moderator]
It sounds like you've already done the right thing for enabling Flash Player in Firefox, but you might double-check:
In general, there will be a plug-in icon on the left side of the address bar, which you can use to enable/disable Flash Player.
Both pages work fine for me, so I think your intuition about authorizing the plug-in is right.
I also don't think this is going to help you solve the crash, but step by step instructions on how to reproduce it, and a link to a page the demonstrates the problem would be useful.
Please see the following guide on how to report a crash or error: