Yes....position your cusor on the box up in the top left corner of the dialog box and your cusor will change to directional arrows indicating that you can then drag & drop the dialog box to another position on the screen.
Then...when you have postioned it, click the box next to it and a check mark appears, indicating that you've lock the dialog box at that position on the screen. Use the slider control to change the background appearance from light to dark , or vice-versa.
Also...it seems to sometimes forget where you placed it so you may have to reposition it everytime you start an SH4 session.
(sounds like a bloody bug!)