Ford Mondeo Estate - Shuddering when accelerating - Schmoo27

Hi Folks

I have a charming old Ford Mondeo Estate, 1.8L and 2003 reg. When driving to work this morning, I noticed a shudder everytime I put my foot down to accelerate (fairly hard but not overly hard). Once I then reach a cruising speed (any speed from 0mph), it seems to run smooth. If I gently acceleerate, there doesn't appear much shuddering at all.

I know it definitelty isn't the balancing; have checked the tyres for bulges, have tried the steering on both left and right locks and can find no clicking, have checked the wheel nuts (all fine), and checked the engine which appears to be stable on the mounts.

In addition, when driving over local roads at normal speeds there is a loudish clunking noise, like a bush is worn?

Is it possibe that it can be an inner drive shaft, and is the inner drive shaft near side or off side?

I'm just clutching at the innder DS; any other theories?

Car, other than the shuddering, drives and handles fine.

Oh and one more random, the fuel economy appears to have improved as well (normal tank used to give me 400 miles, now giving aorund 440-450 miles).

Help!

Cheers

Schmoo