From: Bostek Nostram
Now we have tried it and it plays after one minute. File is 6MB big, so i am guessing it is preloading? Maybe i should get faster server....
There are a couple of things you can do.
1) In preferences, network tab, reduce the bandwidth slider to around 300kbps, this will give more bandwidth to the OS so it can stream the media quicker.
2) Don't use any land based media systems (standard media), LL phish any media urls, to make sure we are not watching porn, this causes delays in broadcasting the texture and the url to your client.
3) Turn off Voice, as this sucks around 1.2mbps of your available bandwidth.
4) Check that you do not have any background programmes running along with SL as this reduces the CPU cycles of your system.
5) Press Ctrl+Shift+2 and watch the lime green dynamic graph bar while the movie is playing. If it rises above 30% of the total usage, this indicates that the data bit stream of the media is too high an overhead on your client/system (I've seen some as high as 90%, causing total freezing of the client). Too high indicates the use of an agressive codec like MP4, your system has to decode that on the fly, adding to potential stresses/loadingings on the client rendering pipelines.
6) Open the QuickTime player, go into preferences, network/connection, choose your actual type of connection (don't use automatic setting), also play with the buffer/cache slider between Instant on, to short delay.
7) Check the media data bit rate, if its above 1.2mbps, chances are, the movie will stop start and have a long delay before playing as it fills your cache.

Turn off Autoscale in land settings (if you must use land settings to stream media), and use the Align texture on the playing media, using the correct resolution sized prim face. This can reduce the client rendering loadings by upto 50%.