This is actually for Windows 7 64-bit. I haven't even tried running this in Linux yet, I just know from previous experience that my older 21" HP monitor had problems with the DVI -> VGA converter.
And I'm using the newest Windows Update driver, and it has recognized the monitor by name in the device manager.
Open the AMD control center, goto my digital screens and change the /over-/underscan slider. That's it. And non of your screens has problems with the dvi-to-vga converter, because there is no such converter. It's simple an adapter for the DVI-I port, that carries the analog vga signal anyway. The problem was almost sure an unsupported combination of resolution and refresh rate.