gluUnProject

I am using gluUnProject in order to get object co-ords back in order to translate an object via mouse/keyboard use. The co-ords do not appear to be correct! Can anyone shed some light on this please. (2D project)

check to faq http://www.frii.com/~martz/oglfaq/
also u are sticking in the correct z value in your gluproject(…) use glReadPixels to find it out.
also be aware in gl window coord (0,0) is at the bottomleft of the screen