Did you try installing TV monitor drivers?
I understand that some LCD's require drivers to display appropriately even when connecting through VGA port.
If device manager is detecting your monitor as “Plug and Play Monitor" or “Generic PnP Monitor”, then the drivers are not installed. In that case, contact the monitor manufacturer in order to obtain the .INF file to install the driver. Once you have the .INF, right-click on "Plug and Play Monitor" or “Generic PnP Monitor” and choose "Update Driver", and refer to the monitor's .INF file.
When you try to set it up, you should have to go to the display Devices and set up the Dual Display. You should have two displays. One as a Monitor and one as a Digital Television. You also have to set the Refresh Rate and aspect ratio. Display rate should equal the HDTV like 60 or 120. 60 is standard TV low setting, some HDTV's are faster. For VGA you may try 60.
I have a Samsung LN40C500F3F and I set mine up differently. I have my Dell 720p monitor plugged into VGA because that is all it can handle. Then I plugged a DVI to HDMI converter into my DVI plug and a HDMI cord that goes to my TV's only HDMI in PORT. Works great. I adjusted my TV setting to match the display RATIO on my Computer. If you exceed the setting for your video then it can cause problems. Normal TV Herz is 60. You might want to start there. I have no clue what all the specifics on the standard on CPU HD 2000/3000 specifics for TV output.
Try Adjusting the TV a bit. I dont know what the max resolution is for VGA out to a TV. The resolution may be less than HDTV 1080. It may be different for a monitor and a TV.
Try playing with it a bit. I am using my motherboard Intel DG35EC which has integrated HD grapics (720p).
You may get better results with a video card. I dont see why you cant get Dual Display to work with HDMI.