Hi Rich...
thanks for the description. This is exactly how I was doing it after reading the howto...
After releasing reset and power my X5 does:
1. Show the blue DELL screen
2. wait 5-7 seconds
3. give the "ding-dong" sound
4. show me a white screen with blue top "Start Button" + time
5. wait another 5-7 seconds
6. show me the "backup battery empty" sign left of clock
7. freeze there until I press "Start"
8. then show today screen and message "backup empty"
I removed the backup battery so therfore the messages... but no bootloader trick