My Extreme is doing the same thing. Went berserk at R.P. and I couldn't do anything with it. Tried everthing just like you, but nothing worked. Gave up and brought out my GB2. Got back home and fiddled some more, and was intermittent again. Called M/L and sent it in last week. Waiting for them to call and tell me if it's good or bad. You have to have some place to start from to troubleshoot, thought that would be the first thing to eliminate. Like you, I need to find out if it's me or the machine. At any rate I'll post again when I find out.
Oh yeah, $52 from Ore. w/insurance...... :Huh_anim]: