lucy24 - 8:02 am on Oct 21, 2013 (gmt 0)
If you're redirecting rather than simply rewriting, always use a full URL including protocol.
The form with leading slash isn't strictly speaking a relative URL either-- those are the ones with leading directoryname or, in html, leading ../../ and worse. But a leading slash means "reattach whatever you used before" so it doesn't do anything about domain-name canonicalization (and potentially even http vs https if your site goes both ways).
However this should have no effect on whether your redirects work or not. And since you're redirecting rather than rewriting, you can easily see in the address bar where the browser "thinks" it is. Does it say what you expected it to say? If no, there's a problem with the rule. If yes, the problem is elsewhere.