MarketPress with Gridmaker theme, Global Cart NO work

Hello i have a problem to work with a Global cart on MUsite, no work. Only work one cart for each shop (site), and i like work with a one global cart for all site.

I have a new installation on http://www.callevirtual.com with a WPMU 3.2.1 (MU with Sub-domain config) ....
.....with a gridmarket theme (Child of framework) Version.1.3.3

Plugins:
MarketPress Version 2.1.3
Update Notifications version 2.1.2

No work the global cart them i update to the last versión of GridMarket (Framework 1.3.4) and Update Notifications 2.1.3

But i have the same problem , any idea?
You can test it on http://www.callevirtual.com
Thanks