Notices

My first thought is that something is blocking UDP traffic from the server to your phone. Are you behind a firewall? Typically you would be behind a NAT firewall with the typical wifi router set-up. NAT will block UDP unless you have taken extra steps to make it work somehow.

What is the IP address of your laptop that you use to watch video?
What is the IP address of your n900 when you are trying to watch video?

The other possibilities are that you aren't using the correct URL or that mplayer does not support the stream. You could rule those out by trying to run mplayer on your laptop just like you did on your n900.

i am using tano and vlc on my laptop and pc, typing the same Ip address @ N900, thou the video start after sometime on laptop and pc. if its working fine then whats the problem with n900?

laptop ip 192.168.0.101
n900 ip 192.168.0.102

i will try opening all ports but its senseless...

given static ip to n900 and opened all ports tcp/udp 1 to 65535 from router, still the same...

try disabling power control on the wifi interface. never know.......

192.168.*.* is a private network IP so your router is doing NAT. UDP does not work through NAT without other tricks like port forwarding, STUN, or ICE. The software you're using on your laptop or PC might be using STUN or ICE or setting rules on your router via UPnP/Bonjour. I don't think that mplayer supports these options.

Your best bet might be to set up port forwarding on the router for the UDP packets to your n900.

@rfeese: but it works for the lap- and desktop. Something else surely. Are both are cabled and.....

I would look at your router settings. See if there are ports forwarded when playing UDP streams from your laptop or PC. Something is happening to allow the UDP packets to transverse the NAT. The n900 and mplayer are not set up to do the automagic port-forwarding stuff that PCs and Macs are set up to do.