can't connect VGA monitor to DVI port using DVI-i adapter

[clickypiggy]

Im trying to get a 2 monitor setup, my main screen is an acer V233H. 2nd screen is HP w19ev.
i can get both to work in my GPUs VGA port but not in the DVI port with an adapter, they just stay as a black screen but are being picked up by my PC.

is there something im missing?

 

[ffg7]

what videocard do you have as that acer has a dvi port? http://www.engadget.com/products/acer/v233h/specs/