I unfortunately can't help you. But I get the same problem on a Windows PC so you are not alone.
Sorry for yelling - but I would really love to try out this nifty plug-in
I get the same message. Installing as admin through Adobe Extension Manager.
My CS5 (Win7-64bit) is up to date. Using PhotoShop Extended v12.0 64bit. I've got the the 64bit version of PB - tried the v5 and v5.1 - no luck. So I'm guessing PixelBender only installs on the Non-Extended version for some reason.
So I'll yell HELP along with you and hopefully someone can hear us!
YES! I found a solution and it at least works for me
Go this page: http://www.adobe.com/devnet/pixelbender.html and download the Toolkit to your desktop. Open the zip-file and run the program. Then go back and try to install Pixelbender again.
That worked for me
And I wish you the best of luck with it too
I downloaded this toolkit but it also gave an error saying this cant be installed