Mousewheel scrolling is not properly supported by the Flash Player on Mac OSX. There is a bug in the Adobe bug tracker here:

http://bugs.adobe.com/jira/browse/FP-503

But I feel that it’s misleading, and dilutes the issue. Firstly, the title has the word Flex in it. Secondly, it’s complaining about mousewheel support in Safari on Windows XP! Perhaps that is why it currently only has 10 votes.

The actual issue is that the mousewheel doesn’t work in any version of the Flash Player on OSX. It’s just a side-effect that it affects Safari on Windows.

This is a HUGE issue – Flash is all about Rich GUI these days, and OSX users are still without proper mouse support! How could this be an issue with only 10 votes?

At some point, the Flash Player will HAVE to support the Trackpad (with vertical and horizontal scrolling) properly, or risk continuing to look like a piece of ancient technology that doesn’t properly integrate with modern operating systems. I don’t think that’s an exaggeration: OSX users are generally very critical of UI nuances, and this is a biggie!

In the meantime there are a number of workarounds:

• Simple Solution for Mousewheel Events
• AS3 Mousewheel on Mac OSX
• Mac OS X Mouse Wheel Support for ActionScript 3 Flash Applications
• Flash MouseWheel Implementations for Mac OS X

Update: The bug entry has been edited a little to better reflect the problem.
Update: This was fixed and released in Player 10.0.42.34.. Woop! (Wed, 9 Dec, 2009)