Class format error

Dear all:

i have a visad apellet which runs fine on my computer, i start the server
and i put all the classes needed on the server, when i type
http:\\10.35.10.80:80/Vasxpro.html, it runs appellet perfectly fine on my
computer.

however, when i move to a different computer or change computers, and i run
it, it displays

" java.lang.classFormatError.Visad./MathType(invalid Start_pc/length in
local var table)"

is this something new i have to learn about visad ? or what does it tells me
about this error or what is the alternatives i should consider ?
i have no clue what this means ?

thanks,

Isaac