Re-order partslist

Hello;

          There's different ways to skin a cat. I usally balloon my assy., then insert a partslist or bom. Then I rename the balloons  so that their

order makes sense 1,2,3,4, etc. not scattered. That however also scatters the partslist.  Then I'll go into the partslist, & I remember being able to just drag

one line at a time to order things. That works fine in a small bom like the attached. Or I also remember being able to go in & sort the partlist, by item no., either

ascending or descending, and the partlist would be nice and neat & match the balloons.

     For some reason It won't allow me to drag the parts to reorder or to sort, which should be done by simple r.click the partlist, & choose sort.

     Am I forgetting something, or is there a setting? Any help would be appreciated. I've attached the assembly.

 

     rob_d (2010 4.0)

SolidworksBill Of Materials