I too am having this problem.  I did the verify and  the rebuild multiple times.  However, that did not solve the problem.  I was told by Quickbooks Tech Support that I may have to make a new inventory item and make the old inactive.  That will really not solve the problem just cover it up.  Also, if I do this, I will have to redo multiple items and the builds associated with these items since it is happening on more than one item.  Have you come up with a better solution?