Answering my own question: How about other genres with similar issues?
Yes, other genres are affected too, e.g. “Swing” and “Opera”.
An interesting point is, that all of the affected genres have high genre ID numbers. So I went to read the id3v2 specifications and came across this genre id list. And indeed there is a difference: genre ID’s from 0 to 79 are defined by id3v1 whereas ID’s from 80 to 125 (including Folk, Swing, Opera) are Winamp extensions!
Maybe the fuze is capable to interpret the limited range of id3v1 genres only …
But than again, any user defined genre tag strings are working fine, e.g. “MyFolk” instead of “Folk” just works (therefore it is not considered a **** word, tapeworm 
). Strange, isn’t it?
