I'm using Firefox 1.5  (2 crashes my machine before anyone suggests that) and recently I've been getting this error when I look at a forum thread:
Error loading http://www.renderosity.com/FCKeditor/editor/js/fckeditorcode_gecko.js
I can click OK, but then I don't get teh javascript entry box in order to be able to reply to a thread.

Anyone else seen this, or got any ideas?

Just keep refreshing the page until the editor loads.

Heck, I get that error with the most current version of Firefox, the weird thing is that it's fairly random as to when it happens.

Though nruddock's suggestion is a good work-around, since nothing seems to be in the works to address the problem (likely a "It works fine for us!?!" thing").

Why does FF 2 crash your machine? {yup, dumb question, but Im curious..Im using FF 2 and I dont have any of the problems you are having}

I am getting that error as well from time to time, mostlywhen opening a forum thread... not even when replying.

So far, I have tracked it to my software firewall who seems to block firefox for whatever reason.
Usually, I have to delete firefox from the list of authorized applications on the firewall, re-add it and reboot to make the problem go away.

I am using PC Cillin.

Quote - Why does FF 2 crash your machine? {yup, dumb question, but Im curious..Im using FF 2 and I dont have any of the problems you are having}

No idea why. I would get memory errors, a quick blue screen of death and then my maching would reboot.  A few times it wouldn't even boot into safe mode, which was annoying I can tell you.

 I checked a few FF forums and quite a few people had the issue.  mozilla were refusing to accept any blame, they blamed my memory card, so in the end I uninstalled it and went back to 1.5 and it's been fine ever since.  

That's weird, I'm using FF2 with only 512 RAM and all is well.

I'm using FF2 and I also get this error occasionally.

I haven't tracked it very scientifically, but it does seem to occur more often if I try to scroll the page or click links, etc, before the page is fully loaded.

You could see if it is any of the Firefox-Extensions witj Firefox 2.x that is the trouble.
Go to start programs, Firefox, Firefox-(Safe Mode) and then see what happens. If all is ok then I bet it is one of the Firefox-Extensions so then your need to get out of safe mode so close Firefox down and open it up again and disable Firefox-Extensions one at a time or all of them and turn them back on one at a time checking web site after each change.

Good idea Hewee..alot of the extensions and addons dont work so well, or at all with FF 2 that work fine in 1.5

There is a site too that list extensions that don't get along with other extensions too but I don't know the link.