LS or someone capable ... help!

[[N]Lancier]

I have a GTS 450 gigabyte graphic card 1gb i think and a samsung syncmaster 932Bplus monitor 19 " i think, Histwar new GUI needs resolution above 1280 so when i look at display settings i maximum see 1280*1040 32bit but i searched for gts 450 it supports above, so i customize resolution at graph card settings to 1366*768 for example but histwar game shows maximum 1280 again why why why. My monitor block it? it can not be that bad!