The only reason I can think of for this is, that some programs use lowercase base32 encoding for the sha1, while Gnutella always uses uppercase base32:
Base32 - Wikipedia, the free encyclopedia

__________________

-> put this banner into your own signature! <-
--
Erst im Spiel lebt der Mensch.
Nur ludantaj homoj vivas.
GnuFU.net - Gnutella For Users
Draketo.de - Shortstories, Poems, Music and strange Ideas.