Autodesk Inventor

[#1]

I'm running IV2012 Pro SP2 and in some assemblies, the iMates of subassemblies do not show up.  I've tried all permutation od iMate glyph visibility to no avail.  If I drop the same subassembly into a new assembly, the iMates are available.  How do I get them back on?  I'm not about to recreate the assembly (It's an iAssembly), so that is not an option.  Am I stuck manually constraining my fastener subassemblies?  Other parts in the assembly have their iMates show up fine.

iMates on flange fine.

iMates on fasteners missing.  Show up fine in other assemblies.

[#2]

Alright, this must be a bug.  It turns out the iMates were already consumed.  But the fastener assembly was free to be dragged around until I put in contraints.  After deleting the iMate contraint it's back.  This is very odd behvaior.  No red + sign indicating that anything was wrong.