My problem turned out to be the double platinum plugs. I either got two bad sets in a row, or my car just does not like them. I installed a set of OE single platinum plugs & it has been flawless since.
AHA ! According to the Ford parts guy (NOT the service guy, he's a SpEd) "the Zetec (and possibly the Duratec too?) takes a special fine wire plug. It will fire under low voltage whereas the non OE plugs won't", which is why at WOT my car ran fine, and at part throttle and at idle it would miss. Un-FREEKIN-believable !!! All this stress and work and talking and asking, and it's nothing but the plugs. So to any of you experiencing bucking who have just changed their plugs, go IMMEDIATELY to your local Ford dealer and get the specific plug for your application. The parts guy said "you'll see the catalog number is extremely long because there are many specific plugs for some of these Ford engines". It may not help you all, but I'm betting it will help alot of you. Good luck, Ken 99 SE Zetec
KUDOS to you Ken for going the extra mile & doing some technical research for us!! Thanks man!
-------------------- Must be that jumbly-wumbly thing happening again.