Picked up a 2006 Ford Focus 1.6 manual a few days ago. It idles steady at about 1000rpm when warm (~90deg). On the flat, when I depress the clutch, the revs drop a little bit (to about 850-900). However, I have a sloped drive and when the car is inclined (the front is elevated compared to the back) the revs drop to a steady idle of ~750rpm.

Any ideas?