How do we get IUR entries created for accounts payable entry with inter unit GL

We can't seen to get IUR entry created with voucher post.  Example set up - the main AP/GL bu is 945  it is GAAP only LEDGER.  inter unit GL is 445 and is STAT and GAAP.  When entering voucher for 945, with GL BU 445 and running voucher post, the IUR entry is not getting created on vchr acctg line - any suggestions on how to get this to work when the SETID controlling tableset control for both is 945 and 945 has only GAAP