This is in reference to my question yesterday about sub panel grounding. So if my sub panel came with a ground bar on either side of the breaker mounts, are one or both of them isolated from the case and are all the neutrals supposed to be on the isolated bar and the bare wires all attached to the case grounded bar? If this is the case and all off the neutrals and grounds are presently attached together, then how do I fix the problem if there is not enough wire to swap sides with the neutrals and grounds?
Yes, the neutral bar should be isolated from the case and all neutrals should be connected to an isolated bar.
You can purchase another bar with isolation mounts and connect it (with a heavy-gauge [4Ga is typical] white wire) to the first neutral bar if needed to provide adequate neutral bar space. Likewise for a non-isolated ground bar, if needed. NOT having to do this sort of foolishness is one reason for leaving adequate wire in the first place, but presumably whoever wired this wrong was also of the "I want it neat and tidy and no excess wire" mindset.
This question and answer might provide some insight and pictures to look at: Can I extend the ground/bus bar in a main service to accomodate subpanel equipment ground?