Glad I could help! BTW, I didn't say this before, but those keystrokes are the equivalent of home and end on the MBP keyboard. They'll perform the same function in a word processor, an e-mail message, on a web site, etc. Just so you know.
This works but only if you have focus on a message in the preview area. If you have a message selected, this will work. If you're in mail but something else is selected / in focus then this shortcut will not work.