Recently active questions in Wuala tagged with groups

Can I share files with one person and them edit and replace the files in my space? Or in a space that we both can access? Needs to be private other than the two of us. Sorry if this is a newbie question - I think I can maybe do this in groups? But I can't tell from the FAQs and guides.

Hi!
I have several machines running wuala (2 of them in commandline mode). A friend just invited me to a group. The invitation got lost or maybe (is this possible?) arrived on one of the commandline clients where i could not answer it. Beside that i send a few group invites to my friend but none of them arrived yet.
How long does it take until they should arrive? Is it necessary to restart wuala?
Matthias