On his recent arrest 
This news item (published by Keyhān newspaper, in Persian  on 7 March 2010) gives the reason for Mr Panahi's recent arrest. Briefly, according to Keyhān, Mr Panahi had been secretly producing a film at his home, a film that the newspaper calls "anti-régime" (alleyh-e nezām) and aimed at being released outside Iran. Keyhān says that there has not been any "party" going on at Mr Panahi's home at the time of arrests and the people arrested had not been "guests", but a number of people working on the film at issue. Keyhān cites the source of this news to Sobh-e Sǎdegh, and says "according to a knowledgeable source", but I have not looked into the latter publication.