I have a suspicion that up to now <applet archive="../applets/xxx.jar"
was supported. However I suspect it may not be working in 1.6.  You
have to put your jars in an absolute directory (unsuited for offline
use), or downstream in a child,  but not in a sibling directory.

I ran into this before with reading URLs.  I could not use ../ to get
at sibling directories.  

If ithis is so, I will need to upload duplicate copies of various
jars.  Phht.  Further I wonder what Java does when it gets asked to
load the same classes from two different jars.