How to change subtitles codepage?
Type this in the console: sub_codepage latin2

How to pass custom parameters to MPlayer?
Type this in the console: mp_more "your stuff goes here"

How to change associated files' icon?
Type this in the console: fileicon 2, where 2 is number from 0 to 5, and associate the files again. To see what the icons look like right-click the rulesPlayer shortcut/properties/change icon

Why my screen color corrections won't affect the video inside rulesPlayer?
Because it is an overlay surface. Use overlay color controls of your video card or the built in color controls.

The videos appear too bright, what should I do?
First check the overlay color controls of your video. You can also try this solution posted in the forum - http://www.dsource.org/forums/viewtopic.php?t=2299

Can I make the left mouse drag the window instead of pausing the movie?
Type this (no quotes): "bind mouse1 @dragwindow" . Note that it works only with the primary mouse button.