I've read several blogs on-line and this seems to be a regular issue. I've always had the same problem. I get the problem right off the bat, or it works great at first, then after 20-30 minutes it starts cutting out. I've tried listening to stations with lower bit rates, but once the problem shows up the only way to get rid of it is to restart/logoff my computer. Strangely, it works fine, as mentioned above, but then goes right back to cutting off (rebuffering stream). By the way, I had this problem way before V8.0. The station in question were KICKRADIO (256kbps) and RockRadio1 (192 kbps).
I spoke to a Mac specialist about this and here's what he had to offer:
1) The problem may be coming from the Server used by the station.
2) Some of these stations monitor use and after a certain amount of time, you get bumped.
3) Although it may be a different station, it may still come from the same company (ie same server).
During this phone conversation with the tech, I was getting a rebuff every 10-15 seconds. I changed it to another station and the problem went away.
This is my recommendation. For those of you having this problem, post what station(s) you're listening to. Maybe, there's a hand full of stations (servers) who are the culprits. I'll post my updates as I keep track.