Trying to Wireshark this rtmp stream (please help)

[fastidious]

I used Wireshark to get the rtmp link to a stream I am watching on this webpage:
http://isramedia.tk/2/%D7%A2%D7%A8%D...8-%D7%97%D7%99
(this stream is working 24 hours a day)

I got this info from Wireshark:
rtmp://live.yycast.com:1935/live/_definst_
nexter_5234

So I tried to run it with MPlayer on Ubuntu linux (12.04 "precise") with:

rtmpdump -v -r rtmp://live.yycast.com:1935/live/_definst_ -a live/_definst_ -W http://cdn.yycast.com/player/player.swf -p "http://isramedia.tk/2/%D7%A2%D7%A8%D7%95%D7%A6%D7%99%D7%9D-%D7%9E%D7%99%D7%A9%D7%A8%D7%90%D7%9C/%D7%A2%D7%A8%D7%95%D7%A5-2-%D7%A9%D7%99%D7%93%D7%95%D7%A8-%D7%97%D7%99" -y nexter_5234 | mplayer -

Adding quotation marks doesn't work either:

rtmpdump -v -r "rtmp://live.yycast.com:1935/live/_definst_" -a "live/_definst_" -W "http://cdn.yycast.com/player/player.swf" -p "http://isramedia.tk/2/%D7%A2%D7%A8%D7%95%D7%A6%D7%99%D7%9D-%D7%9E%D7%99%D7%A9%D7%A8%D7%90%D7%9C/%D7%A2%D7%A8%D7%95%D7%A5-2-%D7%A9%D7%99%D7%93%D7%95%D7%A8-%D7%97%D7%99" -y "nexter_5234" | mplayer -

I get this error msg:

RTMPDump v2.4
(c) 2010 Andrej Stepanchuk, Howard Chu, The Flvstreamer Team; license: GPL
WARNING: You haven't specified an output file (-o filename), using stdout
Connecting ...
MPlayer svn r34540 (Ubuntu), built with gcc-4.6 (C) 2000-2012 MPlayer Team
mplayer: could not connect to socket
mplayer: No such file or directory
Failed to open LIRC support. You will not be able to use your remote control.

Playing -.
Reading from stdin...
INFO: Connected...
ERROR: Closing connection: NetStream.Play.Failed
libavformat version 53.21.0 (external)
Mismatching header version 53.19.0


Exiting... (End of file)

Could anyone help me fix the command I'm using, please?