Welcome to aximusers.com.
It sounds like you have corrupted the ROM.
Did you carry out a CF flash update or use the Dell utility ?
Download a fresh copy of the files from the web, making sure you have the correct version for your Axim. (
www.p2btech.com)
P25_NK-H-07170300EN.IMG for Axim Advance (400MHz) or
P25_NK-L-07170300EN.IMG for the 300Mhz unit
Copy this to a clear CF card and use this to carry out a ROM update using the 4 button combination.
MAKE SURE you have the axim running on mains power.
Hopefully this will cure your problem