either with installed or remote mathjax, when writing latex code into a question i keep on getting error messages like that:
Question2Answer query failed:
INSERT INTO qa_posts (categoryid, type, parentid, userid, cookieid, createip, title, content, format, tags, notify, created) VALUES (_utf8 '', _utf8 'Q', NULL, _utf8 '2', NULL, INET_ATON(_utf8 '109.91.176.191'), _utf8 'latex testfrage', _utf8 '<p>\n </p>\n<pre>\n\\begin{equation}\n\\Delta =\\sum_{i=1}^N w_i (x_i - \\bar{x})^2 .\n\\end{equation}\nIt is a good idea to number equations, but we can have a\nequation without a number by writing\n\\begin{equation}\nP(x) = \\frac{x - a}{b - a} , \\nonumber\n\\end{equation}</pre>', _utf8 'html', _utf8 'latex', _utf8 '@', NOW())
Error 1452: Cannot add or update a child row: a foreign key constraint fails (`biophysika`.`qa_posts`, CONSTRAINT `qa_posts_ibfk_3` FOREIGN KEY (`categoryid`) REFERENCES `qa_categories` (`categoryid`) ON DELETE SET NULL)
