Tentei por muito tempo (horas) gravar o streaming do link.
Instalei os programas que você usa, descobri que estes programas não gravam streaming RA com link pnm e rtsp.
Procurei sites com soluções, testei as dicas e não consegui. Testei todas as alternativas citadas no site, mas não obtive sucesso.
Para gravar o tipo de streaming do link citado, será necessário estes programas: Streambox VCR, Offline Explorer Pro/Enterprise ou Real7ime Converter.
Abaixo o texto completo:

Recording media streamed through PNM protocol (also known as PNA)
Some .ram files may have a couple of links instead of only one (like in the following example). One of them usually uses RTSP protocol, the other one - PNM protocol.
rtsp://a1552.v7870d.c7870.g.vr.akamaistream.net/ondemand/7/1552/7870/v0001/mitstorage.download.akamai.com/7870/18/18.085/f02/strang-18085-lec-mit-llab-18jan2001-0001-iso-220k.rm
--stop--
pnm://a1552.v7870d.c7870.g.vr.akamaistream.net/ondemand/7/1552/7870/v0001/mitstorage.download.akamai.com/7870/18/18.085/f02/strang-18085-lec-mit-llab-18jan2001-0001-iso-220k.rm
The aforecited RAM file has the RTSP link:
rtsp://a1552.v7870d.c7870.g.vr.akamaistream.net/ondemand/7/1552/7870/v0001/mitstorage.download.akamai.com/7870/18/18.085/f02/strang-18085-lec-mit-llab-18jan2001-0001-iso-220k.rm
and the PNM link:
pnm://a1552.v7870d.c7870.g.vr.akamaistream.net/ondemand/7/1552/7870/v0001/mitstorage.download.akamai.com/7870/18/18.085/f02/strang-18085-lec-mit-llab-18jan2001-0001-iso-220k.rm
PNM and RTSP are just different transport protocols. PNM was used before RTSP was created. RTSP is much more widely used and is a preferred protocol for RealVideo, RealAudio as well as Windows Media. PNM is usually not used on the newest servers, but such streams are not very rare.
If RAM, SMIL, RPM or any other metafile has PNM (PNA) link only, you may try to use RTSP or HTTP protocol instead of PNM with the software that doesn't work with the PNM protocol (The only programs that can download PNM streams are Streambox VCR, Offline Explorer Pro/Enterprise and Real7ime Converter).
For example, imagine you have the following pnm URL:
pnm://www.site.com/somedir/somestream.rm
First of all change pnm:// to rtsp:// or http://. Try to record the stream with your stream recorder.
rtsp://www.site.com/somedir/somestream.rm
http://www.site.com/...r/somestream.rm If you still can't download your stream, try adding or changing the port number like in the following example:
rtsp://www.site.com:554/somedir/somestream.rm (RTSP port is used)
rtsp://www.site.com:7070/somedir/somestream.rm (PNM port is used)
rtsp://www.site.com:8080/somedir/somestream.rm (HTTP port is used)
http://www.site.com:...r/somestream.rm (RTSP port is used)
http://www.site.com:...r/somestream.rm (PNM port is used)
where 554 is a default RTSP port, 7070 is a default PNM port, 80 and 8080 are default HTTP ports.

PS:
- o link que você quer gravar é este:
http://swetv.com/web.../lynette256.ram- mas o link verdadeiro para o vídeo é este: pnm://www.swetv.com/sidewalks/lynette256.rm
Já é tarde, tenho que trabalhar hoje, mas vou continuar procurando soluções para este seu problema.
Talvez queira testas os programas indicados e tentar gravar seu streaming