[ffmpeg with librtmp] Problem downloading from Justin.tv

[jamba]

I have trouble saving from justin.tv using ffmpeg that have librtmp enable, although I did manage success with another site, veemi for example.

ffmpeg -i "rtmp://68.68.30.184/live/_definst_ app=live/_definst_ pageUrl=http://www.veemi.com/embed.php?v=locapasion4&vw=650&vh=450 swfurl=http://www.veemi.com/player/player-licensed.swf playpath=locapasion4" -acodec copy -vcodec copy dump.flv

and if I try to save the video from justin.tv it always failed. this one for example

ffmpeg -i "rtmp://199.9.251.72/app pageUrl=http://www.twitch.tv/peacefuljay swfUrl=http://www-cdn.justin.tv/widgets/live_site_player.r3262f88719e6b856324ee5dd5d8b1d7595cf76b4.swf playpath=jtv_27Eo5oNZ4_YFwD3u jtv="5ecae6814a36f8ccc0e4c5d4d0cbfdf2381b4b9a:{\"swfDomains\": [\"justin.tv\", \"jtvx.com\", \"xarth.com\", \"twitchtv.com\", \"twitch.tv\", \"wdtinc.com\", \"imapweather.com\", \"facebook.com\", \"starcrafting.com\"], \"streamName\": \"jtv_27Eo5oNZ4_YFwD3u\", \"expiration\": 1317238268.588141, \"server\": \"video44-1\"}" swfVfy=1"  -acodec copy -vcodec copy dump.flv

dunno where I did wrong. does librtmp works differently on ffmpeg?
please help about this. Thanks