Sticky Throttle When Changing Gear

[Haggis X]

I have noticed that I am having a bit of a problem withe the throttle when changing gear. on random occasions when I go to change up in gear I depress the clutch, lift my foot from the gas and you hear the engine rev as though I haven't lifted my foot of the gas. I have checked to see if there are any fault codes, but there are none recorded. it is as though the throttle is  is momentarily sticking.

Any Ideas as to the best way to remedy this.

[wicket73]

I had a similar problem with two fiesta 1.4 tdci's.went back to my local dealers but they never could tell me what it was.both cars were only 6 months old.