light knock sound when changing gear

Have a ford focus MKII 1.6 with only 3,000 miles on it but it has this occasional light Tap/knock sound when e.g changing from 1st to 2nd and at the point it takes up drive (when coming off the clutch ) as if the driveshafts are snatching slightly ; more noticeable at lower speeds also sometimes happens from 2nd to 3rd and all other change ups are fine, is this fairly normal given it's a front wheel drive? Have been told by a Ford service manager who test drove it, that they all do this and nothing to worry about and it's the noise from the two cables that go from the gear lever to the gearbox/ clutch but has anyone else noticed this with theirs, just annoys the hell out of me!!

P.S as bizarre as it sounds; it's a similar noise as if you flick your tongue off the roof of your mouth so to speak!!

Cheers Pete