There seems to be a problem with skinning Switch. Where a height and width is specified in the [Main] section of the skin.ini file, Switch seems to ignore these values and use a larger size instead, filling the rest of the window with white.
This is a bug in the skinning engine, however I have a temporary solution for this problem. This problem seems to be happening where a transparency is not used. If this is the case, delete the skin.rgn file from the skin zip if found and add the following to the [Skin] section of the skin.ini file.
This will specify a transparent color of pink to be used. As long as there is no pink in your skin (that specific pink color), then the skin should display correctly.
I aim to fix this problem with the next release of Switch (hopefully to be released early next week).
Please email me if this solution does or doesn't work.