Spawn Chunks not loaded

After setting up a repeating command block that has this commad in it->

/say loaded

At the coordinated x=0 and z=0, and even doing the /setworldspawn command directly on top of it, after moving far enough away from the spawn chunks, the commandblock will stop saying "loaded", and not commandblocks seem to work.

This could badly effect some adventure and commandblock oriented maps.