I created some "invisible" PNG (8bit 30x30pix) buttons in Photoshop, but I can't get them to work.

The idea is to have a picture from (a part) of an original remote control and put some "invisible" buttons on top of the buttons on the bitmap. Then I can use it as it was the real remote.

But it doesn't work. The buttons are invisible, I add actions to it and it works in the simulator but not on the Pronto 9400 itself. I try it with pagejumps as action.
I am a newbie with Photoshop, I didn't see an option to put an Alphachannel.

Other question.
What does the "scroll area on control panel" settings? Last tab on System page's properties. I hope it does something as a scrollbar on a laptop's touchpad.

Last question.
On my old Pronto 890 it was possible to resize panels with the mouse. Am I the onlly one who used this or do I overlook something and is it still possible?