SOLVED!
un grazie a nbache sul forum di hyperion, che mi ha spiegato quanto segue:Are you using the Italian translation of AmiUpdate? If so, you may need to revert to English until somebody releases an updated Italian catalog, and you have installed that. Unfortunately, in the latest versions of AmiUpdate, the author has (inadvertently, I assume ;-)) shifted the internal string IDs in relation to the ones in the catalog, so you sometimes get wrong messages and labels in the program, until a new translation compiled with the new IDs is installed. I'm not sure if that is (part of) what you are seeing, but it might be.
Probably the easiest solution for now is to delete the existing catalog from your AmiUpdate/catalogs/italian/ drawer, and reboot, so AmiUpdate automatically falls back to the builtin English, which doesn't have the problem.
ho rinominato il catalogo italiano e riavviato amiupdate.
malgrado le scritte siano ancora in italiano, adesso amiupdate funziona e ho scaricato e installato senza problemi l'update allìaos4.1fe e 2 update di file MUI.
BRAVO nbache!