Ok, I had a chance to look at your DEV_CorpOrder Pool8.mdb and as mentioned earlier, the field name cannot be found in the underlying query.
Open your [z-rush orders1] select query and you will notice the field is named as shown below...
Expr1: LTL-UPS wt Break
This means you are selecting the [LTL-UPS wt Break] from your [Service Table] and you are renaming it to Expr1.
Remove the Expr1: from the field name and it will work.
ET