OK, I tried deleting the proline21.cab file and did a re-install, no difference.....
So i again loaded the aircraft.....fps starts dropping to 0.6, 0.3 and out of frustration, i start clicking all my mouse buttons, i start hitting the 2d pop up gauges. pressing and clicking, pressing and clicking etc. Well i pulled up the engine/navigation display 2d popup (shift+ 2) and i clicked one of the black buttons on the left side and whoa-la! The sim comes out of the funk that its in and fps return to normal parameters. I get actually very good performace.
this experience has been very strange, but im glad i am now able to use the aircraft.
Big thank you to those who responded. I hope this finding may help someone else.
Take care