After a long wait for a LTS version of Ubuntu I finally installed their latest release the Ubuntu 12.04 LTS Precise Pangolin, I installed it on my Compaq CQ40 the AMD Turion X2 64-bit with ATI Radeon version.

The installation went smoothly and when I attached my LED monitor (Samsung SyncMaster SA300) and try to configure the multi-monitor setting, I got this error message "The selected configuration for displays could not be applied".