Content-type: text/html; charset=ISO-8990
Is that a.) a problem in any way, and b.) is there a way to do it without modifying the source? I know some things (like keepalives) are very touchy about what headers you modify; we couldn't find anything that seemed to require the charset option for Content-type, but there's also no easy way (that I could find) to remove it - so that might indicate that you aren't supposed to remove it.
(For instance, you can remove a lot of the other stuff by adding "ServerTokens Prod" to your apache conf file, so I wonder why there's no way to strip the charset out - or did I just miss it?)