[Con] Altering Stockpile makes Class Items Unusable

Summary:
Chaganging allowed items in stockpile has the effect that some items cant be stored anymore in the stockpile.
Items if noticed:spool of thread, rabbit toy, stack of stone bricks

Steps to reproduce:
make a stockpile
change the allowed items
change it back to all
let weaver spin some spool of thread

Expected result:
Weaver will store items in stockpile

Actual result:
Weaver does not store items in stockpile and places them on the ground instead. Ony a new stockpile solves the problem.

Version:
Alpha 7 r 183

Attachment: