The contents of the archives javathreads.jar and
javathreads.zip are the same.

Some versions of Netscape Navigator try to 
use the javathreads.jar file for a "Smart Update,"
so if you encounter this and the accompanying error
message, please download the javathreads.zip file.

You can use jar to unpack javathreads.zip, as is,
or you can rename the file to javathreads.jar first.