By the way, I'm using an image that I was having problems with the file changes. We note that the stamp of the methods are not stored in UTF-8, in the common cases should have no problem, but if someone puts extended in the sign ASCII characters are stored wrong. That what I discovered working with the port of Glorp, if they need a reference.
I think that the stamp is stored in UTF-8 in 3.10 as well (at least it does in the OLPC Etoys image). But #getPreambleFrom:at: is looking at the sequence backward so that it cannot decode it properly.
-- Yoshiki