OK many thanks to Dave and Rui! :) - missing Jack dev files was the problem
it seems that after my upgrade the dev files were not installed
so I installed them and was able to compile qtractor with vst - I tested
it with discoDSP/highlife sampler and it works
one problem though...I am not able to use LV2 plugs
how do I set the 'configure' to include the services listed below?
Version: 0.4.7
Build: Dec 28 2010 11:57:17
MPEG-1 Audio Layer 3 (libmad) file support disabled.
Pitch-shifting support (librubberband) disabled.
OSC service support (liblo) disabled.
DSSI Plug-in support disabled.
LV2 Plug-in support disabled.
JACK Session support disabled.