I was holding a bunch of cash in FTEXX, needed for taxes next April--wanted to keep it separate from more general savings in FDRXX. I went back and read the prospectus and decided that municipals, which will be hit slowly but hard by the housing crash, were not the right place to keep money at the moment--I cashed it out and put it in a 6 month CD. Pays less but safer. I'm inclined to think, in a worst case scenario, that FIDO will protect those MM funds that are heavily used but might not protect one that was both less used and very clear, in its prospectus, about risk.
DrH