Alright, I posted this in another forum but unfortunatley not too many people run through that post....
Have a blade flutter problem, I had found that the main shaft collar had worked itself loose, I tightened it back down and thought it was fixed. It flew fine for a while through loops and rolls then all the sudden the blades flutter for about 10 seconds (it was way up there it took a little time to bring her down) and then it just stopped. I noticed that I had thought I had heard it later during forward flight but only for an instant. I'm also having troubles with blade tracking, I can never get it just right, possible link between fluttering and impossible blade tracking??? I've tried half turns full turns and even partial turns on the links but nothing seems to work. Help with EITHER problem would be veyr appreciated, thanks in advance all!!!

You blades are probably fluttering because the blades aren't tracking right. Have you checked your spindle (feathering shaft) to make sure is isn't bent? If it is bent, that would make the tracking pretty much impossible.

Look into your dampeners aswell. It's possible they're worn out. Replace them, along with your main spindle, and see if it improves.

To me, blade flutter would point to worn out dampeners.

Well I'm pretty sure the feathering shaft is ok, I visually inspected it before, but hey, human eyes aren't the greates things for detecting small variances. I'll replace it anywho just to be safe. Where do I get replacement dampners??? I don't ever remember seeing them in my LHS (not that I've looked). Is there like a hardware store or non-hobbyshop where I could buy them? Particularly somewhere that I can buy them in bulk (like 10-20 at a time, I have a horrible habbit of losing small things like these things)???
Guys thanks very much, I think I'm willing to bet that you've located the prob (sorry AJ I know you recommended it in my last post so thanks to you too of course!!!)

I think the dampeners come as a set with the main head mast, i'm not sure. Or maybe it was with the feathering shaft. I don't know if you can get them seperately?

Well I replaced everything.
No where near as bad but I still can't get the blades into a perfect disk and it still sounds like it wants to flutter. Is it possible my head speed is to high for plastic blades and pretty much all plastic head????

Yes, it is. I've had no luck with plastic blades in tracking. Many pilots won't even use them. Either go wood or go carbon. The plastic blades flex way to much.