Well, no, they ought to be OK.
I went over to my wife's XP box and tried this with "Hello, World" and, lo and behold, I got the same error! Now, I'm interested.
So I did a little Googling, and came up with
this link. The upshot of this is that jview reports NoClassDefFoundError if the class file's version number is later than it expects. Since it's so old, it expects quite an old version number, older than any current JDK uses.
To produce class files that jview can handle from a modern JDK, you have to give the "-target 1.1" switch to javac when you compile them:
javac -target 1.1 myProgram.java
I tried this and it indeed works.
Interesting question!
[ October 21, 2003: Message edited by: Ernest Friedman-Hill ]