IP - Char Relationship - Feature or Bug??

All, I think I've discovered a bug in IP but I want to verify that this isn't a case of "a feature, not a bug".

1. I create a r/t cube for planning, a simple DSO (to create a characteristic relationship), and then I create the aforementioned characteristic relationship.

For simplicity sake, my cube involves 0MATERIAL, 0VERSION, 0SALESORG, 0SALES_OFF, 0SALES_GRP, 0CURRENCY, and 0AMOUNT. My characteristic relationship only uses 0SALESORG, 0SALES_OFF, and 0SALES_GRP and is set to "Excl. #". The "Excl #" makes it display better.

2. Because I want to plan on some NULL (#) values for 0SALES_OFF and 0SALES_GRP, I include them in my DSO. For example, I have a line w/ 1100 for 0SALESORG, 0003 for 0SALES_OFF, and no value for 0SALES_GRP. This allows me plan data at that level on my cube even though my char relationship is set to "Excl #".

3. I then create a simple planning function to copy data, only changing the 0VERSION. However, when I try to execute the planning function IP throws the following error:

"To-value 1 for sub-process 1 produces following errors

Cannot find reference data for characteristic combination"

If I change the char relationships not to "Excl #" then I can run the Copy Planning Function without a problem.

It seems to me if I can plan data manually then I should also be able to plan it with a function. So my question is .... is this a bug? Should I be able to do this? If not, what part shouldn't I be able to do?

I'd open an OSS note but experience tells me SAP will dismiss it as a "consulting issue".