"Hidden lines" in the config?
I was doing a lab on OSPF over FR (using NBMA type) in which I accidentally put in the OSPF neighbor statement in the spokes. When I check the config. it actually doesn't show up but yet if I do use the 'no' option the IOS gives me of those 'OSPF-5-ADJCHG' message saying that it has been de-configured. This is on a 3600 running 12.4(16). Damn buggy!