Firefox weirdness


  • My Silverlight 4 app is not (completely) working on Firefox 3.6.3. The app starts up normally, but the WCF calls are extremely slow (like 100x slower -- no kidding).  What is weird is that if I open the Firebug or YSlow console, it suddenly speeds up.  This also happens if I select a blank (Untitled) tab, and then switch back to the Silverlight app tab -- it suddenly speeds up as if it cached a bunch of stuff while on the blank tab.

    This is unrelated to the posts about localhost, too many plugins, and network traffic.  From the same machine my app runs normally on  IE8 and Google Chrome. It used to run normally on Firefox, but at some point it stopped -- I don't know when.

    Has anyone else been experiencing this?  Any ideas would be appreciated.

    Monday, June 21, 2010 12:26 AM

All replies

  •  I use firefox 3.6.3.

     My application use silverlight 4.

     When i've moved from sl3 to 4 i've seen the difference. But nothing when i moved from 3.6 to 3.6.1, 3.6.2, 3.6.3 even with my wcf calls.

     Have you try to uninstall firefox and install it ? Have you try to disable your plugin ? Update them ?

    Monday, June 21, 2010 10:05 AM
  • Thank you for your reply.  Yes, I have uninstalled and reinstalled FF, and I have tried disabling/updating the plugins.

    I have tried running the app with FF 3.0.11 on Windows XP and that works fine.

    The computer where I am having the problem is running Windows 7.  I would like to try running the app with FF 3.6.3 on a different Windows 7 machine that doesn't have my development environment installed. Can I email you directly and send you a link to my app?

    Monday, June 21, 2010 11:39 AM
  • i'm using windows xp not 7 on my development computer .

    Have you test a software like fiddler ? I think something might be wrong on your computer. You should try it on another computer with win 7.

    yes you can !

    and don't forget to tell me how long is your web service call without firefox 3.6.3 and with to see if i got the same problem. (the problem could be from your application :p i hope it's not ^^)

    Tuesday, June 22, 2010 3:22 AM
  • I actually have the same issue with both ASP and SL on the localhost webserver from visual studio. If I put my applications on a "normal" IIS server on localhost firefox is as fast as IE but on the VS webserver it moves like a snail compared to IE.

    Plugins I use on firefox are adblock plus, noscript and some nasa skin.

    Tuesday, June 22, 2010 3:45 AM
  •  My webservice is on a dev server that could be the reason why FF is still as fast as before.

    Do your wcf project is in the same solution of your application ?

    If yes, try to move it into another solution.

    Tuesday, June 22, 2010 4:07 AM
  • The latest news is that I installed Firefox 3.6.3 on a new Windows 7 machine that does not have any sort of development environment installed. It is essentially a brand new machine just purchased at the store. On this machine FF still runs very slowly.  When a ChildWindow is opened a photo is supposed to be displayed, but this does not work on FF, so my app is essentially broken on FF. It works great on IE and Chrome.


    I have used fiddler to examine the web traffic (on my development machine) and it appears that Silverlight makes a WCF call and the request/response is fairly fast, but something that happens after that is very slow. Everything else Silverlight-related is very fast -- menus, resizing windows, typing, buttons, repainting, etc. all work as expected.


    Another weird thing is that performance seems to be dependent on whether FF is maximized (by 'maximized' I do not mean 'full-screen'). There is a listbox of photos along the left hand side of the screen. This populates very slowly when FF is maximized, but much faster when FF is not maximized.  When FF is doing whatever it is doing during the slow period, the FF menus are unresponsive -- you can click on the FF Help menu or try to close FF and nothing happens for about a minute.  The CPU usage is around 60-75% during the slow period.


    Tuesday, June 22, 2010 10:57 AM
  •  @Ozzy1

    Thanks that fixed it

    Wednesday, June 23, 2010 3:22 AM
  •  Weird. Do you know if it's only on localhost ? Or also when your application is deploy on the web ?

    If wes, it's a big problem. We couldn't force users to disable ipv6.

    Wednesday, June 23, 2010 3:48 AM
  • NetQvist's issue is only for localhost and unrelated to the problem I am having with FF. 

    After doing a lot of research, I am ready to conclude that this is a FF bug. It seems that FF version 3.6.3 has some problems with Silverlight.  There are a number of similar bugs entered on the Mozilla bug tracker.

    Wednesday, June 23, 2010 7:31 AM
  • Hahaha while we were talking firefox asked me to upgrade to 3.6.4 :)

    Is the problem fixed with firefox 3.6.4 ?

    Thursday, June 24, 2010 4:25 AM
  • I also upgraded to 3.6.4.  Some problems have been fixed, but not all -- my app is still broken :-(

    I left a note on bugzilla.  Hopefully, they will fix it before they release the final version.

    Thursday, June 24, 2010 7:29 AM
  •  woaw they were quick to answer !

    You just have to use IE or chrome for localhost until release become available :/

    Thursday, June 24, 2010 8:02 AM
  • FF 3.6.6 is still broken :-(
    Monday, June 28, 2010 10:56 AM