Is it possible to sign only part of an applet? Ie, have an applet that pops up no security warnings about being signed, but if some particular function is used (that requires privileges) then use the signed jar?
From what I can tell, some (perhaps most) browsers will pop up the warning for a signed applet even if you don't request privileges at all at execution time. I'd rather avoid that if possible.
Try splitting your code into an unsigned jar and a signed jar.