Vibrato thumping?

[boobtube21]

My Vibrolux's vibrato has a little thumping--not ticking--noise that changes speed with the speed knob, but is not affected by the intensity knob. It works fine...a little choppy for my taste, and loses some intensity at the highest speed setting, but other than that works and sounds ok. It does this both with the original footswitch and with a shorted rca plug.

So far I've tried (suggestions from the amp d-bugging page linked by yankeerob):

-Moving cathode cap to the board, it was grounded to the vibrato jack.
-remelting wax on the eyelet board with a hairdryer.
-randomly moving wires around.
-there is already a .02 cap from the 10M to ground, installed by someone other than me.

It's a little better now since moving the cap/melting the wax, but still there, and plenty audible at bedroom levels. I'm no tech so I don't know which wires souldn't be run alongside others, but I did find a couple of forums online with guys suggesting moving the virbrato leads away from tone leads...I think I already did that just moving stuff around...and that seems to be more a suggested solution for ticking anyway.

Anyone got any ideas? Thanks!