New PC - installed Spybot 1.5 first, and immunized. Later installed Firefox. Silly me.
Now Spybot won't offer to do the Firefox immunizations, like it does on another PC that had Firefox before I upgraded from 1.4 to 1.5.

Is this a bug?
Any workarounds that are less trouble than uninstalling & reinstalling Spybot ? (Which I will probably do in a day or so if nobody has any better ideas).