[RMMV] MV WINDOWSKIN QUESTION

Been playing with MV more, but I ran into something weird when putting together windowskins.



The background seems to seep out of the edges. It's hard to see, but look at the bottom corners.

Is there something I'm doing wrong? I mean, I could move the window out one pixel in the graphic file, but I thought the program would keep this from happening. Any insight would be appreciated ^_^