Actually, what you are probably seeing is the name of your BB, as shown in your WiFi or other network devices. Typically, the name a BB is given is "BlackBerry" appended with the last 4 characters of the BB PIN. So, your BB PIN must end in 8D1A. I do not believe there is any way to, on the BB, change that. But, on my WAP, I can rename any device that is presently attached to it...but I do that via my WAP interface, not on the BB device itself.
Hope that helps!
Occam's Razor nearly always applies when troubleshooting technology issues!
If anyone has been helpful to you, please show your appreciation by clicking the button inside of their post. Please click here and read, along with the threads to which it links, for helpful information to guide you as you proceed. I always recommend that you treat your BlackBerry like any other computing device, including using a regular backup schedule...click here for an article with instructions.