'Surfing The Void' set for August 23 release
Band return to Croatian bash a year after they pulled out due to illness
'He's officially a live member,' says Jamie Reynolds
Band play small venues as part of comeback
Band make 'Flashover' available to hear free
Carl Barat-narrated film airs in London
Simon Taylor-Davies says headline tent show will be first major airing
Acts will join Kasabian, Pavement and Massive Attack at the event
Long-awaited second effort finally nearing completion