[andrewflnr]

> how do you keep the self-reproducing probes "on-task" from one generation to the next?

This is, indeed, the exact question one must ask before attempting to build and launch biological Von Neumann probes.

[Windchaser]

I think it applies to non-biological Von Neumann probes as well. It'll apply to any system that can mutate, even if that mutation is just cosmic rays flipping the bits on a hard drive.