Mac Pro and HP L2335 monitor?

Has anyone had any experience connecting a HP L2335 monitor to a 2.66Ghz Mac Pro with the NVIDIA GeForce 7300 graphics card? The monitor displays the Apple logo as it is booting up but then goes into sleep mode. It appears the Mac Pro is throwing the monitor out of sync -- to restore it to a setting that will work on the old computer (G4) I have to reconnect to the G4, and start up in Safe Mode to reset the preferences.

Thanks for your help.