[rtpg]

I know for a long time there was an issue with Flash not supporting 64 bit browsers (and a browser without flash was hard to sell)

[cozzyd]

I don't think this is a real issue? (64-bit firefox supported 32-bit flash, at least on Linux).

[eridius]

That can't possibly be the issue. Plugins like Flash run in a separate process, which can remain 32-bit if required to do so by the plugin while the browser itself goes 64-bit.