Follow these directions carefully.
To get back to stock:
1. Grab the SBF File
You must start the process with your phone running the official 2.3.340. If you have already upgraded to gingerbread grab this 2.3.340 sbf file.... 2.3.340 Official SBF file
2. Grab RSDlite
You must use RSDLite to use the sbf file from step 1 .... RSDLite
3. Grab the Drivers
4. Run RSDLite and sbf your phone back to 2.3.340
5. go into recovery and wipe data (otherwise you will bootloop)
__________________________________________________ ________________
1. Download the following file and place on the root of your sdcard.
File size = 175.8 MB (184313550 bytes)
md5sum = 52c88ab0c2954f1a1624f72e502175cc
Direct Download - Mirror 1
Rooted Droid X - Mirror 1
Rooted Droid X - Mirror 2
Rooted Droid X - Mirror 3
2. Put phone into bootstrap recovery
3. Install the file you downloaded above
4. Sit back and watch (Your phone will bootloop for approx 30 secs, if any longer than that, pull battery and restart your phone.
You should now have gingerbread and it should be rooted.
5. You have to use D2 Bootstrap on Gingerbread, DX bootstrap won't work.