Lyx dependencies, index sorting ' Operator'

["Gudjon I. Gudjonsson" <gudjon@gudjon.org>]

Hi
    Does anyone on the list know what might be missing from my texlive when I 
get the following error message:

"LyX: Done!
Warning: Index sorting failed
----------------------------------------
LyX's automatic index sorting algorithm faced
problems with the entry ' Operator'.
Please specify the sorting of this entry manually, as
explained in the User Guide."

My package compiles perfectly on my computer but not when using pdebuild. 
There is some texlive package missing. texlive-full is too large but it is 
timeconsuming to search for the missing package. Can anyone help me?

Regards
Gudjon