Lars,
I think unclobber is an excellent fix! I had the exact same problem that you are describing when building the Logger. I definetely think unclobber should be the default. It would surprise me if there is any code out there relying on the clobbering effect. If they are, we might be doing them a favor by breaking their code so that they can fix it.
why not fold the -unclobber patch into the standard db_ behavior and do without a new switch altogether? I can't think of anyone actually needing to clobber the variables in the calling code.