Doug:

In the Receivables Company Profile there is a new setting that allows you to prevent users from posting the other side of an AR transaction to the AR control account. This is primarily a benefit with Adjustments where users would get confused and distribute to the AR control account resulting in the debit and credit both hitting the AR control account when the transaction reaches the GL.

I've seen cases where the OE Clearing account was defined to be the AR control account so that may be your situation.

To allow posting to proceed, edit the Receivables Company Profile.