Clean tree (rm -rf..; gzip -dc | tar xvf), no 64-bit elements. The -Uuse64bitall -Uuse64bitint took care of the issue (for now, anyway -- I still have not tested against our vendor's library).

Are your binary distributions locked into a specific directory, or are they able to be relocated? If I can relocate them (and have multiple installed simultaneously), I would surely consider it, although I might need to get my SA involved (political boundaries, not skill boundaries).