I just had a look and it looks like the positioning of the combobox needs tweaking.
The arrow is slightly cut off at all resolutions.
I'll fix it for the next version.
The program will run in any resolution.
1024*768 is the lowest resolution it will run in without scrollbars, but it looks awful.
1280*960 looks reasonable
1680*1050 is the resolution I use and probably looks best at this resolution since its what I see.
1920X1200 should be fine.
DPI should be normal (96DPI), with normal font size, there seems to be an issue with .NET that causes problems with scaling for people using other DPI.