I don't have Altium 10, but there are a few things that maybe happening.
1) You have the 'snap-to-grid' on and the grid size quite large.
2) Mouse/graphics driver issues.
Try reinstalling your video and mouse drivers.
Also check you don't have any weird mouse options enabled.
3) The component your moving has a free pin which is far away from the component itself.
Altium jumps the mouse position to one of the component pins as you drag it, so if you have a pin way off in the distance it may jump to that.
This is only likely to be the cause if you have been editing components or making your own.