I have this problem too. Divx doesn' t work in Firefox and Opera. I installed and deinstalled it 4 times. But allways the same shit. It works first, but after PC restarting it doesn't work again....

'''SOLUTiON to get the DiVX WebPlayer HiQ BETA 4 working in FiREFOX 5''' '''this is also working w/ Firefox 4.* !''' ''in 3. Steps'' I have found a '''Solution''', you have to Install an '''Older Version as 10''' of '''Flash Player''' to get the Divx Web Player HiQ working on youtube. And when you '''want''' to '''use Firefox 4+ or 5 w/ the HiQ Divx''' you '''also have to do''' the '''First and Second Step!''' '''First''' you have to '''Edit''' [''Text-Editor''] the '''"install.rdf"''' File in the '''Install Folder of Divx''' '''C:\Program Files\DivX\DivX Plus Web Player\firefox\html5video\install.rdf''' Change '''Line 12''' '''maxVersion''' into Version '''5''' -> '''type 5.*''' ''( em:maxVersion 5.* /em:maxVersion )'' '''Second''' you go into this Folder below and Edit the install.rdf there too '''C:\Program Files\DivX\DivX Plus Web Player\firefox\wpa\install.rdf''' Change '''Line 17''' '''maxVersion''' also into Version '''5''' -> '''type 5.*''' ''( em:maxVersion 5.* /em:maxVersion )'' '''Third-Important-Last-Step''' Go to '''Adobe Site''' "Archived Flash Player versions", there you Download those '''two''': "Uninstall Flash Player" and "Flash Player 9.0.280" [http://download.macromedia.com/pub/flashplayer/current/uninstall_flash_player.exe] [http://fpdownload.macromedia.com/get/flashplayer/installers/archive/fp9r280_plus_archive.zip] When you have downloaded '''both''', '''close all Browser''' Use '''uninstall_flash_player.exe''' Flash is now Deinstalled. You '''MUST''' '''now Install an Older Version of Flash to get the Divx WebPlayer working correctly!''' Unpack from '''fp9r280_plus_archive.zip''' this File: '''flashplayer9r280_win.exe''' and Install it. Finish. You can also use the Directlink below: '''''Flash Uninstaller''''': [http://www.megaupload.com/?d=RGOLF6J8] '''''Flash 9.0.280 Installer''''': [http://www.megaupload.com/?d=EU6PC43A] '''-----------------------------------------------------------------''' '''Very Very Odd ..''' '''could it be that Flash 10 blocks the''' '''Divx HiQ web player in his actual Version,''' '''or just youtube linked to use Flash 10 only if its installed?''' '''-----------------------------------------------------------------''' ''Start Firefox and enjoy divx web player on youtube'' If you want to use '''HTML5 Player''' on '''youtube''', go [http://www.youtube.com/html5] there you can join the Testing Phase. Now you are able to watch the videos without using the Adobe Flash Player which sucks since v.10.* because of getting '''Bluescreen on Windows''', '''how embarrassing Adobe!''' i have attached a Screenshot which proof it works. enjoy html5 or Divx on youtube without Bluescreen ^^

'''''@drasko ''''' try the '''Third''' step in my post, after that i was able to use divx web player with youtube. it sounds odd but after installing an older version of flash it works.