Hello George1,
Renumbering of Reference Designators In PowerPCB4.0 can be done under ECO Mode.
When you enter ECO Mode,ther is ICON Button for renumbering Reference Designator
U1---->Ux
On clicking this u will se a dialog box AutoRenumber which consists of
Prefix List (All the possible Refernce Des including JUMPER must be listed in this LIST).
Cell Size,Precedence and some other options are also present.
For renumbering JUMPERS just click its Ref Des from List the decide the precedence on board and also unselect Bottom Layer.
Just after this click OK Tab.
The Renumbering will be done.
I hope this will help u....
Please let me know ...if this was what u wanted??
regards
Wilson