help!! my floyd rose's pivot studs have a strange problem...

I'll make a guess: You switched to 10s, and the action was much higher, so you tried to adjust the pivot studs to fix it. If so, that would be the incorrect way to go about this change. You should first re-level the the bridge by increasing the tension on the trem springs (beneath rear cover) to compensate the higher string tension of the 10s. This would be the usual first step in setting up for a new gauge. If you did not, the higher tension of the 10s will cause the bridge plate to tilt forward, raising the string heights. After the bridge is re-leveled and the strings return to their normal action height (with proper neck relief), then you can adjust the action height using the bridge studs.

If you stripped it, replace the stud. It should not cost very much. Look here:

http://www.stewmac.com/shop/Bridges,_tailpieces/Floyd_Rose_tremolos_and_parts.html

i've adjusted the bridge springs.. so, the base plate was already parallel to the body...this is why i called it strange...because, though i had turn the bridge studs till it really hard to turn anymore, the action still the same, just like when i first started.. they didn't change...what could possibly happened?

Btw, could you give me some instruction... how to do -changing n replacing the pivot studs? thx u

Okay, good about the tension adjustment. Now check the next relief. I realize you were planning to do this anyway, but if you have not yet done it, excessive relief might be raising the action unduly.

As for replacing the stud and insert: I have done this on several Les Pauls, but never on a FR. If only the post is stripped, you probably just back it out of the insert and screw in a new one. If the insert is damaged, it may be a little trickier, as you will need to wedge something firmly into the insert to give you enough purchase (grip) to pull out the insert. Careful not to wiggle the insert out of the hole, as that will damage the wood -- a straight pull is necessary. I generally build a miniature "wheel puller" to do this, using a large hex socket, a bolt that fits or snuggly cross threads into the damaged insert, plus a nut and washer to fit the bolt. A bit of thin wood or thick paper also protects the guitar wood around the insert.

1. Protect the guitar wood around the insert with the thin wood or thick paper.
2. Put the large hex socket over the insert, large opening (6 or 12 point 'hex') against the protected guitar body, and square drive hole up. The socket must be big enough (internal opening and height) to allow the insert to be pulled up into it. Also the square drive hole must be large enough to allow the bolt to pass through it (1/2 or 3/8 in drive should do)
3. Spin the nut onto the bolt. Slide the washer onto the bolt -- the nut should not be able to pass through the washer's hole
4. Put the bolt through the drive hole, through the socket and thread (several turns) or cross-thread it into the insert snuggly. The washer should rest on the top of the socket.
5. Spin the nut down the bolt until it makes contact with the washer (resting on the socket).
6. Use a wrench to tighten slowly and evenly the nut against the washer. As you keep tightening, the bolt should rise out of the socket, pulling the insert with it.

After inspecting the guitar's wood around and inside the insert hole more damage, it should be a simple matter to press in a new insert of the same size as the old. If there is wood damage, you may need to glue a dowl into the original hole, and redrill the repaired area for the insert.