The problem of disappearing backslashes in moodle has languished there for a long time. I hope it has been dealt with in 1.6 It severely limits the usability of TEX filter and makes it very difficult to use resources for delivering content containing code snippets of various programming language.
I posted this elsewhere and have seen random posts regarding this. I am posting it here to draw the attention of the developers and improve the chances of the problem being addressed. Hope you guys can squeeze it in 1.6 release.
vikram solia!