The HD3300 graphics chip can only support two monitors the reason that you have three connectors on the back of your motherboard is so they don't have to supply a DVI->VGA adaptor. So your chip looks like:
Originally Posted by MartjeB
The DVI and VGA are connected to the same "port" on the chip and so can only display the same image. Hope that helps.
| H | ________DVI
| D |-----|
| 3 | '--------VGA
| 3 |
| 0 |
| 0 |--------------Display port
Edit: you need to get an adaptor like http://www.pcsuppliers.co.uk/INU_Pro...P?ref=M852A116 and then use display port + dvi/vga to get the two monitor setup working.