you need to hit the midi map button Ctrl + m then on the vst there is trangle sign, when you press it it should open up to show all the parameters in the ableton style...
depending on what vst you are using u might get mixed results
some will have their parameters named properly (filter cutoff 1 etc) some wont (parameter 0001,0002 etc) and some wont work at all (ableton has problems when there is more than 128 parmeters on a vst,, and just comes up with parameter 1)
lemme know if this is the case as there is a work around...