Setup:

Using KeyClone.

5 boxing on a single PC.

No movement keys whatsoever (not even autorun) are passed from the main to the followers (when specifically using a follower I have to mouse move him). Using KeyClones block-list to prevent the movement key passing.

Runner Problem:

It has happened only half a dozen times to me. One follower - always only one, and not necessarily the same one - will, with no warning take off in the direction it happened to be facing. Usually not a problem, double-clicking in the window (once it has focus) is enough (for me) to stop it. It has however caused one wipe when follower number three took off to say hello to about 6 or 8 Scarlet Crusader friends he saw in the Cathedral wing of SM.

I've been able to see absolutely no pattern to it at all, as it happens so infrequently. I have also noticed that every now and then, one follower will stop following, again so infrequently that establishing any pattern to it is too hard.

Overall, while it did cause one wipe, that's one wipe in 61 levels of playing, so it's not (for me anyway) much of a problem.