PB 12.6 64-Bit Windows Applications - Grid Table unsupported

I was reading this article on deploying 64-Bit applications with PB 12.6 and I was puzzled by one of the items listed in the unsupported features.

http://help.sap.com/saphelp_pb126/helpdata/en/2f/8c548ab5781014944b973cfbb2dec1/content.htm?frameset=/en/2f/8c548ab5781014944b973cfbb2dec1/frameset.htm&current_toc=/en/2f/16f291b5781014af9ce45f1ca8d7d2/plain.htm&node_id=12

Can I get further details on the "Grid table" item listed under unsupported features?

Is this regarding the Grid section for grid datawindows?  If so, what exactly isn't supported in 64-Bit?

Regards,

Mike

http://help.sap.com/saphelp_pb126/helpdata/en/2f/8c548ab5781014944b973cfbb2dec1/content.htm?frameset=/en/2f/8c548ab5781014944b973cfbb2dec1/frameset.htm&current_toc=/en/2f/16f291b5781014af9ce45f1ca8d7d2/plain.htm&node_id=12