Okay, sadly this is a regular problem with the Edge. The use of the bushings is simply something you have to live with.
Every time you use the bar you're wearing a bit off the bushings, so the arm will become looser over time.
Every time you remove/replace the bar in the holder you are basically sheering material off of the bushings, making it become looser even faster.
There are a lot of "tricks" people will give you to tighten up the bushings, but the best way is to simply replace them.
If the bushings are new, and it's tight going in but you still have play in the bar, then the holder itself is loose and it's a simple fix.
Go to www.ibanezrules.com
(swirly banner at the top of the page) and read through Rich's tech pages to learn the easiest, safest way to tighten your arm holder up.
If it's just the bushings, while you're there email Rich for prices and shipping costs to have him send you some new ones. He's one of the nicest salesman you'll ever deal with.
Oh, by the way, Hello everyone! I'm back, I've been concentrating on school lately and haven't spent much time on here but I have some free time and I'm trying to catch up a bit on reading the forums. :-)