am i maybe writing the code wrong?
Looking at your example I think I see your error;
HTML reads like a book, top to bottom; and computers are very literial!
You've put your styles UNDER the webamp script - so what your saying to the computer in english is:
"Make a div called boxthree; render webamp where the box is, then move the box to X position" - You're assuming that it will also move webamp with the box; but webamp is not actually in the box, its just rendered where the box was before you moved it

So the solution is just to move your <style> block into the <head> - that way all of the styles will be read before the HTML is read; and the computer will know to position the box where you want it, then render webamp where the box is.