Thanks. I had already installed those - in fact the whole "Catalyst control center".
Alas, still no luck even after reboot this am. I still cannot access the correct resolution for my screen. The best is 1600x1200. There is no option for 1680x1050. It evidently 'acknowledges' my HP monitor though, it no longer calls it a "generic PnP'
So, to recap - all drivers (HP Monitor [HP_w2007_3.0] and ATI GPU [Catalyst Software Suite] ) installed.
Any other idea's?