Problem setting game resolutions in MAME

[twobad]

I'm running the Ultimarc ArcadeVGA 3000 video card output to an old arcade cabinet with horizontal screen.  Many games no longer display the entire screen - eg.- in Frogger, the frog is below the screen at the start and the score is off the top of the screen.  When I attempt to set the resolution by right clicking on the game title and selecting PROPERTIES then SCREEN I cannot select OK at the bottom.  The RESET box is the lowest part of the window I can get to with my mouse.  The pop up window is not able to be resized - it is of fixed size and even by dragging the window to the top of the screen, I cant get to the bottom of the window to save my settings.  Any thoughts?
TIA,
-=T=-