I'm now using MX, and it seems to respond very slowly to the keyboard and mouse. I'm on a Mac. It's incredibly annoying.

For instance, using the space bar to get the hand tool, or clicking on the "Insert" menu (or an other) to have it open up, or to click a keyframe in the timeline, etc. Basically everything.

I've done nothing to my OS, or to Flash, just installed the upgrade. Could it be memory alotted for he application itself? Why is MX slow?