home, calendar, contacts buttons not working.

[bobjones1000]

Dell Axim 51 - rom 12, using WMDC on Vista Business.
The home, contact, etc. buttons on the bottom of the device do not seem to be working. When I push one of them I get the following message:
"the file "01Button" cannot be opened. Either it is not signed with a trusted certificate or one of its components cannot be found. You might need to reinstall or restore the file".
Not sure why this occurred, although I have been installing and uninstalling various programs since I got the device. However, no original cd was included with the device which I bought off of ebay. Any thoughts on how to correct this.

thanks.

[Mahstah]

You should first try reassigning the button mappings in Settings-->Buttons. If that doesn't work you're going to have to hard reset.