Ok seriously, this is lame.
 

http://img205.imageshack.us/img205/9770/untitledac9.png

Whenever I'm only browsing around sites (with firefox) I get this message. It stops everything from loading and tries to load whatever this is, and once it fails everything goes back to normal after I close it. Sometimes it'll pop up a few minutes later and try again.

I've checked for spyware/virus/etc and it hasn't found anything. I don't know where it comes from, or how to disable it. Nothing in Network Connections is showing that there's a connection retrying itself either.

Showing a cry of OUENDAAAAAAAAN for help here.

It appears that your PC thinks that you are using a PPPOE connection to connect to your Internet. These types of connections are common with DSL and ADSL. They require a user name and password similar to dial-up. If you have an always on (most cable style internet) connection this shouldn't be an issue. It could be that you have an existing PPPOE connection on your PC that may be causing issues you should be able to locate this in your network properties

The most important thing to know is what kind of a device you use to connect to the internet. Is it a USB modem, or is it a router? If you're using a router, you shouldn't see that message at all. If you're using a USB modem, then you computer thinks you have a problem with that modem... which considering that you can post... you probably don't.

I don't have a modem, just a router.

I haven't messed with any router settings which could have caused this message to continuously appear whenever I'm browsing. The thing which I don't understand is that it only happens when I'm browsing websites and nothing else.

While I do have a router, I'm also on ADSL. But in the 3+ years which I've had it (56k for 4 years was awful, srsly) nothing like this has appeared. Hell, if shit like this occurred back then, I would've complained a long time ago. Trust me.

The router's connected to 2 computers, my mother's computer and my own.

Do you still have the software for an older modem installed? Is that possible at all? I can't see that error message arising in conjunction with your router.

Is it possible that someone else installed modem drivers for whatever retarded reason? Check your internet settings in the Control Panel to see if there are any connections listed there that shouldn't be.

Nope, there's nothing there. In my devices all that's listed is my wifi, my current internet connection, and one which is disabled (I don't know what it's for, but it's disabled anyway) and that's it. Still out of ideas here.

It isn't the wifi thing either, because even with the dongle unplugged, I've noticed the message still pops up.

OSUUUUUUUU

Try browsing with IE or any other browser, and if that message doesn't pop up, you've traced the problem to your firefox settings.

Did so for a few hours and it didn't appear. Looking under firefox's settings I can't see anything causing this either.

Then again, it was just a couple of hours in IE. Which I must admit felt terrible.

Ok, it definitely isn't coming up when I'm in IE. But I've checked through firefox's settings and from what I've seen there's nothing there that could fix this.

It seems to be coming up even more now, or whenever I'm in youtube. It's really annoying. Help?

Well, at this point, the simplest solution is to back up your favorites and reinstall Firefox.

Burning a forest to kill weeds? Probably, yeah. But I'd rather do that than deal with a shit-ton of settings in about:config. =\