What might be the problem?

[abel]

Recently I´ve downloaded a torrent with Ebba och Didrik, 9 separate .avi files each one with Swedish subs in .srt format (well, better than none). When I wanted to play them, I am always getting a message like "Unrecognized format for 'D:\Program Files\Azureus\Incoming\Ebba Och Didrik\Ebba Och Didrik - 1x01 - DVDRip.AC3.XviD-CaseyJones.Swe.srt'. No idea what might be wrong, the video and subs files bear an identical name, except of course the suffix. I´ll be grateful for every hint.