I'm attaching new versions of the algebra/mathml->gif filters. The new versions contain a bug fix for the problem Mark Hughes was experiencing with the filters. The problem was due to the way mimetex.cgi looks for its TeX inputs. It first checks the environment variable $QUERY_STRING for its inputs, before looking at its arguments. On Mark's server, Apache/PHP exports its value of $QUERY_STRING (typically something like "id=x&....") to subprocesses launched by php scripts. The fix clears $QUERY_STRING before launching mimetex.cgi. [If you are downloading the filters for the first time, you will need to get additional files from the anonymous cvs in the contrib/algebra and contrib/mathml directories.]
I tried to update the CVS, but it seems to be down since last night.