you need to update your rtmp.

I stole this code from LAGMonkey

I highly recomend that you login via SSH.

first remove any previous packages

Code:
sudo apt-get purge rtmpdump

Then install your dependancies
Code:
sudo apt-get install build-essential git-core checkinstall libssl-dev

then copy and paste this 

Code:
cd ~/ && \
git clone git://git.ffmpeg.org/rtmpdump && \
cd rtmpdump && \
version="$(git log -1 --abbrev-commit | grep commit | cut -d' ' -f2)" && \
make VERSION="v2.4\ $version~git" && \
sudo checkinstall --pakdir "$HOME/Desktop" --pkgname rtmpdump \
--pkgversion "2.4-$version~git" --backup=no --default && sudo ldconfig

This will download, build and then install the latest git version of rtmpdump on your system. Once complete you can type "rtmpdump" and it should give you somthing like the following below (notice the version number)

Code:
rxbmc@xbmc:~$ rtmpdump
RTMPDump v2.4 5d03a4f~git
(c) 2010 Andrej Stepanchuk, Howard Chu, The Flvstreamer Team; license: GPL
original code is not my work but i have used it personally, this was taken from "ron999" over at http://ubuntuforums.org/showthread.php?t=1816737 credit should go to him and the rtmpdump team
__________________________________________________ _________________________________________
Updating RTMPDump

once you have installed RTMPDump from the code above, to update it you will have to do the following. Copy and paste as one SINGLE command.

Code:
cd ~/rtmpdump && \
git pull && \
version="$(git log -1 --abbrev-commit | grep commit | cut -d' ' -f2)" && \
make VERSION="v2.4\ $version~git" && \
sudo checkinstall --pakdir "$HOME/Desktop" --pkgname rtmpdump \
--pkgversion "2.4-$version~git" --backup=no --default && sudo ldconfig

This code takes you to your rtmpdump code folder (git clone), updates it to the latest git version, makes the new version and then installs it for you.

Once again thanks LagMonkey your a star and gets a thumbs up from me.