BPC and Office 2007 documents

Is the following statement true:

"Documents created / used by BPC should be in the Excel 97-2003 format"

I am on the SAP Basis team and new to BPC. We are in the development phase of implmenting BPC 7.5 Patch 6 on Netweaver .

The desktops are running Office 2007 and Office 2010.

I resolved an issue last week for a user that was trying to open a template that was saved in an Excel 2007 format and it would not open. I have another user telling me that his BPC locks up whenever he attempts to open an Excel 2007 "Marco Enabled Workbook" - this is a *.XLSM file. I have two other users telling me that their BPC session "freeze" and need to check with them as to what exactly they are doing when this happens.

Should I be telling my end users that BPC only supports Excel 97-2003 documents and that they should be saving their BPC related documents in this older format?

Thanks in advance for your input