Did you try running linuxconf in console mode and see if your problem is with the gnome-linuxconf GUI rpm? Did you install the gnome-linuxconf rpm? Does this happen under KDE, Gnome or both? I checked bugzilla and I don't see anything related to the problem you are describing.
Linuxconf has been officially depreciated by RedHat. I don't use it and haven't since RH 6.0. I will install it on my RH 7.1 system and see if locks up in anyway.