I swotted up about that Pif, unfortunately the res is tied into the area of your effect in the game. If you manage to up the res/screen size you end up seeing monsters before they 'see' you. Their world-view remains tied to the old res even if yours isn't.
I got a flat screen given to me ages ago and promtly punted it back and dragged my old monitor back (much to my other halfs disgust) because DII looked fecking awfull.
When he gave me his next hand-me-down flat screen and DIII came out I did a bit of rummaging and found out about the res thing. DII goes into a sort of window and I sit further back