Ok, so whenever I install a new window into RPG Maker VX, the window has a border but the window background is a strange white background for every window I install.

This is the window I was trying recently. Notice the red background that's supposed to display, it's in the upper left corner. What I think is displaying is the white space in the lower left, but I'm not totally sure.

That's what the window looks like. I can show more pictures if you want. It looks really messed up.
Can someone explain to me what's going on here and possibly suggest a way to fix it? It's really bothering me because the only window that works is the default RMVX windowskin and it's ugly.