Yeah well...
In the latest (paid/premium) PAIcom ver 0.5i I fixed this issue (PAIcom automatically detects your screen size and places himself in the right spot).
You problably have like a not common screen ratio/size (maybe a laptop screen or a widescreen?).
The only thing you can do rn is play with the screen zoom from the windows settings (on laptops is usually set to 125%... You can set it to 100% and see how PAIcom should've stayed like).
Other then that... You dont have other settings sadly. I might update the demo but I'm not sure. (I quite have a limited time right now and I'm trying to focus on the premium/paid version). STILL, I might fix this issue on the demo version too!