Note: This is just a stopgap release that fixes the System Sounds bug on the Treo 650.
A full KeyCaps650 release is forthcoming. Also, this application will still show up as KeyCaps600 in the Launcher. The program name hasn't been updated yet.
Download newest, modified version here. Feel free to donate money to him instead of me, as I'm no longer using a Treo or maintaining KeyCaps.