Allur, I did this accidentally also, after I did my dock was at the top of the springboard. I simply went back into the installer app, and uninstalled Summerboard, then rebooted the iPhone and it was back to normal. Hope this helps.
Did you try to shut down iBrickr and try to start it up again? Did you reboot the iPhone? If you did all that, Im not sure what else you could try. I just recently started using iBrickr and ran into your problem once before and was able to resolve the issue with a reboot.