Last modified: 2005-12-09 08:07:50 UTC
At <http://en.wikipedia.org/wiki/Square_triangular_number> I just edited a line of TeX. I saved it and reloaded several times. That line of TeX is not getting rendered; all I see is the TeX code itself. (I'm assigning this high priority because we cannot afford to have TeX not functioning; Wikipedia is more successful in mathematics than in any other field and the rate of editing those pages is very very high.)
Your TeX was valid and you tried purging the page cache?