Isolating CDP from weak wood floor


My CDP skips (alot) when my 25lb son dances on the wood floor in front of it (weak joists). I have a solid Manna rack and use MIB bearings under the CDP, but there is really no up/down isolation. I've also tried nothing, bubble wrap and some thick rubber/cork feet--no dice. I just looked at some Solid-Tech discs of silence, which seem like they might work-http://solid-tech.net/isolator.htm. Before I shell out the $$, I thought I'd see if anyone else has faced this problem. Thanks. D
disc
Thanks for the quick turnaround everyone. I appreciate it. In the interests of full disclosure, I need to redo my foundation entirely and re-sister (as they already have been sistered) the joists. My dirt floor basement looks like a convention of drunken screwjacks, standing only because they're nailed to 2x4s. But there are none on the joists under the stereo. Might be time to shift some of the stereo fund to the house fund. I'm going to try the artgum idea and the screwjacks. GSM, I'm holding your solution in reserve.

I really appreciate the help and will report back.
Before spending a lot of cash try mounting the cdp over a bicycle inner tube with just enough air to keep it suspended. Isolate the rack with soft rubber like gum rubber. Also try gum rubber or sorbothane under the cdp. You want to stay away from any hard materials often sold as isolation devices.
Disc, install a jack or two under the offending joist. That's what did to cure a problem similar to yours, only with skipping turntable.
I am sorry to hear that your floor is so weak. Perhaps it is time to consider having the floor or at least it's support, (beams, joists whatever those things are), being professionaly redone altogether. Drunken Screw Jacks make me a bit concerned. Sorry about the down side of things being brought up, but what if the whole family is moved to dance to the music. OH No Mr. Bill.....