I wish Microsoft had just delayed BizTalk 2006 to include the full EDI functionality that R2 has…WOW.
If you right-click on the Party and select EDI Properties then select X12 Properties->Party as Interchange Sender->ACK Generation and Validation Settings there is a checkbox labelled EDI type under the Document Validation Properties. When this box is checked the EDI Receive pipeline strictly checks the EDI data to ensure it is compliant with the EDI specification. For example an R 1/17 field MUST include decimal places. By unchecking this box you’re leaving yourself open to non-EDI compliant data, but will at least allow you to receive the data.
Our suppliers are usually reluctant to change their systems so being able to turn this on/off on a per Party basis is awesome. Again, I wish this functionality had been included in the original BizTalk 2006 release.