[rtmpdump] RTMPDUMP usage unclear

[rtmpdump at pepak.net]

Hi!

I am trying out RTMPDUMP because I would like to add streaming video
support to my video downloader, but I can'rt seem to figure out the
basic operation. Disseting the pages of provider I want to download, I
neded up with this stream URL:

rtmp://88.86.101.151/vod/mp4:PS9_12_3_10_500.f4v
(just one video chosen simply becauise it was the one at the top of
the page at the time I was dissecting it).

This URL is apparently all I need, because Flazr (http://flazr.com/)
will happily download it without asking for any extra data. But for
some reason, I just can't make RTMPDUMP download the stram - when I
use command (with RTMPDUMP 2.2 for Win32):

rtmpdump.exe -r "rtmp://88.86.101.151/vod/mp4:PS9_12_3_10_500.f4v"

it simply informs me that NetStream.Play.StreamNotFound. In verbose
mode,it seems to parse the URL correctly:

DEBUG: Protocol : RTMP
DEBUG: Hostname : 88.86.101.151
DEBUG: Port     : 1935
DEBUG: Playpath : mp4:PS9_12_3_10_500
DEBUG: tcUrl    : rtmp://88.86.101.151:1935/vod

The StreamNotFound error appears as a result of SendPlay message:

...
DEBUG: HandleInvoke, server invoking <_result>
DEBUG: HandleInvoke, received result for method call <createStream>
DEBUG: SendPlay, seekTime=0.00, dLength=0, sending play: mp4:PS9_12_3_10_500
DEBUG: Invoking play
DEBUG: sending ctrl. type: 0x0003
...
DEBUG: RTMP_ClientPacket, received: invoke 191 bytes
DEBUG: (object begin)
DEBUG: Property: NULL
DEBUG: (object begin)
DEBUG: Property: <Name:                     level, STRING:      error>
DEBUG: Property: <Name:                      code, STRING:      NetStream.Play.StreamNotFound>
DEBUG: Property: <Name:               description, STRING:      Failed to play PS9_12_3_10_500; stream not found.>
DEBUG: Property: <Name:                   details, STRING:      PS9_12_3_10_500>
DEBUG: Property: <Name:                  clientid, STRING:      ngu4uy+Y>
DEBUG: (object end)
DEBUG: (object end)

I am at a loss what's wrong. My only guess is that maybe RTMPDUMP
should be requesting stream "mp4:PS9_12_3_10_500.f4v" but it only asks for
"mp4:PS9_12_3_10_500", but of course my knowledge of RTMP is zero so I
am probably wrong.

Any suggestions on what I could try?

Note: At the moment I am simply trying to get the provided binary to
work. I plan to get into the library code later on, when I am sure
that the download actually works and any failures are caused by my
shoddy coding.

Thanks for any help.

Pepak