marketpress is not working.

hi all, i've just downloaded and installed the MarketPress plugin. however the global function isn't working. i used 'network activation' and added a few products to the sub-store. however no global products shown on the main site.

i'm not sure if i have missed some steps or what. may anyone provide me with some guide/instruction.
i just want to have a global store with products of mini-stores shown.

thanks a lot.