can't remove js from page
I can think of 4 things to check in this case, in order of likelihood:


What does the preprocess function stub look like?  Are you using the variable &amp;$vars there, too, or are you using &amp;$variables instead (which is how it appears in the documentation)?  They, of course, have to match.
Have you cleared your cache?  D6 was bad about sometimes needing the cache to be cleared twice.
Is the function actually running?  If not, then there may be a problem with the function name that it is not being recognized, or that the cache has not been cleared (which should be taken care of by checking #2).
Is something messing with the variable afterwards that is inadvertently re-adding the core js file?