Create Favicon with Mac?

I’m trying to create a favicon, but when I attempt to install the plugin for Photoshop (e.g., from Telegraphics, Photoshop says that it couldn’t open because it doesn’t recognize it. Any idea on what I’m doing wrong? Thanks!

Adobe Creative Suite 5
Mac, Intel, OSX 10.8.2, 2.53 GHz Intel Core 2 Duo, 4 GB 1067 MHz DDR3

Hm, I’ve been using that for a long time with no probs in CS5 Mac. There seems to be a newer version on the home page:

How are you trying to install it?

Otherwise, there are online tools for creating a favicon format, such as

thanks - I’m double-clicking to install it. And funny thing about it is that it appears to be installed because when I check under the Plugins pull-down menu, I see it listed.

Hm, have you closed Ps and opened it again?

That did it. Thanks!