I am having the same problem on my notebook (Gateway W350a) with a ATI graphic card (ATI Technologies Inc RS690M [Radeon X1200 Series]).
I have tried with the drivers "ati", "radeon", "radeonhd" and "fglrx", none of which worked properly (if worked at all).
I have a fresh Ubuntu 9.04 installation.
I am having the same problem on my notebook (Gateway W350a) with a ATI graphic card (ATI Technologies Inc RS690M [Radeon X1200 Series]).
I have tried with the drivers "ati", "radeon", "radeonhd" and "fglrx", none of which worked properly (if worked at all).
I have a fresh Ubuntu 9.04 installation.