From your sig you appear to be using a PPC so will have an 060 CPU. In which case you will probably need the 68060.library in the Libs drawer. If I recall correctly you can delete the 68040.library from the floppy to make it possible to be able to boot into the 3.1 Intall disk. But that would mess up being able to do a full install of Workbench from the 6 disk floppy set.
(sorry if this doesn't help or confuses you.. lol)
