I've downloaded a few keyboard themes but when I turn them on in Winterboard it doesn't do anything.

I've checked out both of these videos but they don't work;
[ame=http://www.youtube.com/watch?v=0iPV0bK5jqA]YouTube - how to get and change keypad themes on iphone 3g 3 0[/ame]
[ame=http://www.youtube.com/watch?v=A06xXQRN2i0&feature=related]YouTube - Change Keyboard Themes on 4.0[/ame]

Whenever I try to add the source that it tells me, I just get this message;

Can anyone help please?