Hesitating 1.0i Ax Under Acceleration

[dimensionman]

Hi guys, not sure if anyone has come across this fault before, I have a 1996 1.0i AX with 69k, The car is intermittantly hesitating(misfiring?) on acceleration at lower revs when under labour if you put your foot down hard it overcomes the period of trouble and will rev cleanly to higher engine speeds, also at the same time when cruising in fourth at say 60mph'ish when you lift of and reapply the throttle nothing happens untill the pedal is halfway down the travel and then the acceleration picks up with a jolt, again this is intermittant as a few moments later it is fine again. I have replaced plugs and lead set, and it is annoying me as the rest of the time it drives fine but when it plays up acceleration is so slow because of all the hesitation untill it clears itself again, HELP! B)