Getting this or similar with kdm 4:4.7.4-2 in Wheezy (in a Asus Eee with Radeon HD 6320) --- but even though the screen is black, it seems that the greeter may be there: the mouse cursor changes when over what seems to be an input area... Stopping kdm and starting it again, (/etc/init.d/kdm stop, then start) the greeter shows up normally again (vt7). J Esteves