I've got some class files that open in Netbeans (with .java extension) but in Eclipse I had the following experience:
At first I could not see the content of the class files with jadclipse and I only saw:
A few days later (without any change to eclipse or ...) I could see them but with errors like the ones bellow:
"Couldn't fully decompile method ...
Couldn't resolve all exception handlers in method ...
Overlapped try statements detected. Not all exception handlers will be resolved in the method ..."
But the other day I ran into the first error that I could not see anything again!!!