AMD Radeon 6450 Dual Monitor Issue

Hello,

I currently have two monitors connected to an AMD Radeon 6450 graphics card using a DVI/VGA adapter for one and HDMI cable for the other. Recently the HDMI monitor stopped working and displays a box that has "Check Signal Cable", a red, green and blue box, as well as a grey box with HDMI written in it.

My problem is that when I run the DVI/VGA monitor by itself everything is fine, but once I connect the HDMI monitor both screens go blank and the DVI/VGA monitor displays a box saying "No Input."

I can connect a TV though HDMI with no problems, using the same cord I used for the monitor. I want to try to troubleshoot the monitor, but am unable to do so, and my warranty is over.

I'm running Windows 7 64 Bit with the latest ATI Catalyst Control Center and driver. The monitor that causes the problem is a 23" Samsung SyncMaster SA350.

I haven't been able to find anybody with the same problem and all dual monitor recommendations I could find didn't work. Any help or ideas would be greatly appreciated.