Additionally, the same videos play just fine in IE.

This has been reported in Adobe forums and elsewhere and appears to be a problem with version 9,0,115,0 of Flash. Reverting to an older version of the Flash player plugin can solve it.
See this mozillaZine forum post http://forums.mozillazine.org/viewtopic.php?p=3249140#3249140

Also see http://forums.mozillazine.org/viewtopic.php?p=3253563#3253563 later in the same thread. Running a flash utility program has also fixed it for some.

You're welcome

I found this:

02/09/2008 10:42:50 AM

This should fix the problem:
I have had the same problem for the past few weeks. It seems to have started when firefox updated itself. I tried the troubleshooting instructions on the adobe web site but had no success. I then tried mozilla's troubleshooting instructions which led me to the folder: C:\Program Files\Mozilla Firefox\plugins. I noticed that the dll for flash player(WPSWF32.dll) was not in this folder. I did a search and found the file in C:\Windows\System32\Macromed\Flash. I copied and pasted the dll to the "plugins" folder and my problem was fixed.

here:
http://www.adobe.com/cfusion/webforums/forum/messageview.cfm?forumid=44&catid=184&threadid=1330412&enterthread=y

and it worked.

Thank you Quarantine! That fixed it for me too!

"On a 64 bit system, locate NPSWF32.dll and put it in C:\Program Files (x86)\Mozilla Firefox 3 Beta 5\plugins
Restart Firefox.
THIS WORKS"

Thank you very much, that worked like a charm!!

Hi All
i had the same problem. Videos stopping after 2 seconds. Turns out there was a problem with my sound card. I installed the correct drivers and that sorted out the problem.
hope this helps
Adrian

Hi all,
I am using the JW Media Player (http://www.jeroenwijering.com/?item=JW_FLV_Media_Player) and was having the same problems listed here with my videos stopping at 2-3 seconds. I have found a solution that will work and does not require any work for your clients to move files or change any settings. Here is what will fix this problem:

I'm 99.999% sure this is the solution. Cue points is the answer!! All the videos now work seamlessly. You can keep the same file name and everything, I just added 5-6 cue points and for the type, change it from "Event" to "Navigation". Make sure there is one at the very beginning(00:00:00) and the very end for sure, but throw a couple randomly in the middle. Please try this and post your results here and let me know if it worked for you....then if applicable...send a check or money or to....lol, just kidding.

I really hope this will fix everyones problem!!

If you don't know what Cue Points are, please read this (http://livedocs.adobe.com/flash/9.0/main/wwhelp/wwhimpl/common/html/wwhelp.htm?context=LiveDocs_Parts&file=00002947.html)

For any further information, please read this thread (http://www.jeroenwijering.com/?thread=10338)

Well on my system I installed FF3 in a different folder than the default one & YT videos wouldn't play. Tried all the uninstall/install routines that worked for others but they didn't work for me.

What did work for me was to copy the 'nppdf32.dll' file from C:\Program Files\Mozilla Firefox\plugins to the plugins directory for my FF3 install (in my case it's C:\Program Files\Mozilla Firefox3\plugins). Restarted Firefox and working fine now. It seems the plugin couldn't find it's way to the non-default location for some reason.

I'm using WinXP Pro with Firefox 3 RC1. Hope this helps someone.

Hey guys, I have another resolution for this problem based on Pete's cue points, but simple enough for those amongst us who just want to watch their YouTube or Facebook videos.

If you go to Start Menu > Programs > QuickTime > QuickTime Player

and pull up an instance of the player, you can then
go to Edit > Preferences > QuickTime Preferences > Streaming

Look at the second box where it says Enable Instant-On and remove the check mark from this box.

Click Apply and then OK.

Restart Firefox (I prefer to go through TaskMan and kill the process so I can save all my open tabs in Firefox, but feel free to do your own thing).

(For the more advanced or knowledge craving amongst you, Instant-On is a setting in QuickTime to play streaming media without waiting for the buffer. It is enabled by default and unchecking it using the scientific method of changing only one thing per a browser restart led me to the conclusion that this was the fix)

Dan Rogul