This may be a dumb question but, did you actually drag the purified glyph down to the first of the 4 slots before trying to click the research button? As far as I know, if a person tries to research a glyph and fail to discover anything, they get a failed message and their character actually gets physically injured. A second possibility, though less likely, is that you already have researched that spell and now it's just saying already known. Is the spell showing up in your magic book at all?
Edit: never mind, if you are near death seems it's working... is the stat bar trained all the way up in theoretical knowledge then?