before next week ?

[Girard Henri]

Hardy has  problems on my computer acer aspire dualcore.
with gustsy they don't exist
when i updated to hardy or from a fresh install I can't come back to kdm 
when working on kde or kde4 i got a black greyish screen and the only way to 
start again is reboot... very annoying !
with gdm it doesn't do it ... I wonder if they is not another session 
running behind (gnome ) ?
need help thanks
henri