Don't understand what you mean when you say there is no OTA update available. My phone is trying to update but always fails the update.
The Droid X hasn't had an OTA for a long time. Has this been failing for awhile? The reason it is probably failing is because you removed bloatware from your device. Did you remove any of system apps? If so, this method wouldn't work. This is simply another way to get the phone to check for an update if it says "your phone is up to date".