Do you have any more info on this? I've had customers return a few broken objects - they've spontaneously unlinked themselves. These are wings, and they flap the usual way - central prim runs a timer, sends out a linked message, all the feather prims use that to move to a new position. Today I was finally able to sort-of reproduce the problem:
* Turn up the flapping speed, so the child prims are getting linked messages fast.
* Go to a laggy sim
* While the timer's running (and the wings are flapping), issue more wing commands that make them change flexiness/size/position
... That's the part I'm not sure about. I've got 2 wings to break, but I don't have a fixed set of commands that always causes it. Anyway, my "hide" command makes the prims shrink down to a tiny size, and move to ZERO_VECTOR (local coordinates, obviously). Sometimes, what I see is that the prims have gone down in size, but they haven't moved to the root prim's location. Once this happens, if I detach the wings and then rez them on the ground, they'll be separate unlinked objects. And the prim sizes/positions do exceed the link limits. But if a child prim tries to move to an invalid position, the function call is supposed to fail, it's not supposed to get to the new position and then fail the link distance check and come unlinked. At least, that's how I read the Wiki.
Here's the call I'm making:
else if (cmd == "in")
{
llSetPrimitiveParams([PRIM_POSITION, ZERO_VECTOR,
PRIM_SIZE, <0.02, 0.02, 0.02>]);
}
So... if that's causing what I'm seeing, then it looks like the prim params list is applied backwards. Which doesn't make much sense.
The workaround I can think of is to make that 2 function calls. Won't look as nice, but it might be safes where scripts will randomly not execute some functions, and execute others in the same logic block. I can't think of any way to protect against that.
So anyway... if you have any more details about your testing, and if you've found a pattern for what does not work, please post that here. And if anyone else has any ideas, they're most welcome

Thanks,
Ziggy