Tone arm bounces

This very weird! When I play an album at a very high volume my tone arm starts to bounce. It will play albums start to finish at moderate levels with no problem at all. I have checked alignment and weight issues and they seem to be good. Clearaudio Avantgard table with Stradivari cart. The system is in a temporary room and may not be ideal. Could it be bass from my rear ported Watt Puppy 6's? Thoughts-----------

Sounds like acoustic feedback to me..Coming from the floors all the way back to your turntable amd arm...
Agree acoustical feedback.
Try some mass loading below TT. under the TT, or under the stand on floor. At least 70 to 100 pounds.
Cement bricks are good and cheap temporary fix.
This sounds like a problem related to the cartridge choice and arm compatability. I would check the effective mass of the arm as well as the cartridge then look up the calculator online that determines the resonant frequency. From what you are describing the resonant frequency is too high and not within acceptable inaudible frequencies below 15 Hz where the human ear can't recognize them. You interpret it as a bouncing arm but really the cartridge you chose isn't compatible with the arm on your turntable. Although I could be wrong.
What I left out was that at high volume compatability issues really become obvious. At low to normal volume it may not be audible so you assume because it sounds good to you that all is well. The other thing you forgot to mention was the dynamic compliance of your cartridge, is it, low, medium or high? Why did you choose that cartridge, was there a particular reason, was it recommended to you??? With a little more info we can figure it out. Send me an e-mail if you're interested and still want to cure your turntable of this problem.
Try sending someone an e-mail with the new format---doesn't work like it used to.
Upgrade ASAP!!
It's a Clearaudio Turntable with a very nice Clearudio Cart so I think the table and cart are compatible. Stradivari 2 is the cart. Its driving me crazy. Like I said, low to med volume it plays and sounds very, very nice. I get the volume any where past half way and the tone arm will start to bounce-----right across the LP!
If you are not using a record clamp you might want to get one. Perhaps vibrations being induced in the record itself, as distinct from the platter, are throwing the stylus out of the groove. A clamp would presumably help that.

Also, although I realize that you have checked the tracking force, if it is not set at or near the upper limit of the range recommended by the cartridge manufacturer you might try raising it to that point.

-- Al
Try taping a coin to your tonearm, above the cartridge and rebalancing it. If that works, they make weights that can be more elegantly installed
Al makes a good point with regards to tracking force.

With few exceptions, I've found that optimal tracking occurs closer to the maximum recommended VTF as opposed to the minimum.

And a sidenote, you can do more damage to records with insufficient, than excessive, VTF.
Thanks for all the feedback. I do have a record clamp and I have checked The weight, all seems to be good. Frustrated!!!!!!!!!!!