I unfortunately have seen a lot of cases where Go-back causes boot problems. I service end users' machines often and deal with this fairly often. Go-back appears to act just like a boot-sector virus. (Places itself in the MBR and loads before the OS starts its boot process). If anything modifies or attpemts to "fix" the MBR, Go-back breaks, often causing the machine not to boot, crash on boot or run very unstable. For that reason, I'm not a big fan of that particular utility. The fix? I've had to do everything from simply trying to boot several times to ghosting the whole drive to another HD and experimenting with rewriting the MBR. (ghost the drive so you don't lose everything if something goes wrong)
I wish I had a hard and fast routine that always works, but in the case of go-back, each situation is vastly different.
Best of luck. If you have a spare drive that'll hold your data, try ghosting it. Sometimes even that alone will make the thing boot.