Well, for the past 2 days now I have been having these issues with my Internet. I can't load a page with out exiting and refreshing everything, my post sometimes won't be posted, and websites wont load up. I also keep getting Java messages saying that JavaScript may be offline. So, I've reinstalled Firefox and Java today, and is there anything that might help me out?

Is it any specific sites where this happens most often?
The usual first steps:
1) Run a virus and malware check.
2) Try a different browser, to eliminate a Firefox problem specifically.
3) Turn your modem off, count to twenty, turn it back on.

Java and Javascript have nothing in common but the name.
When uninstalling Firefox, be sure to also remove the folder
C:\Documents and Settings\<username>\Application Data\Mozilla\Firefox (2000/XP)
C:\Users\<username>\AppData\Roaming\Mozilla\Firefox (Vista/7)
But before you do that, go in the folder Profiles\<random string>.default and make backups of the files (depending on what you want to save)
bookmarks.html (all your bookmarks)
signons<number>.txt (all your saved passwords)
key3.db (required to decrypt and actually use the passwords - specific for each installation, which is why you can't use the one from the new install to decrypt the passwords from the old one)
This will remove ALL modifications you've done to firefox, any extensions and skins you've installed, any settings you've changed, and will allow you to restart at a completely clean plate.

Quick semi-related question, whatever happened to that virus, it was called C something, that was supposed to destroy all of our computers? One day it was big news, now I don't know anything about it.

Conficker? That one is still out there infecting.

That's weird...I installed an update and it seems to be fine now...

Yeah, I was referring specifically to Conficker-C, as that seemed to be the one people were most worried about. What is it supposed to do aside from disabling some windows anti-virus and updating programs?

I have a specific problem when trying to access The Guardian (UK newspaper website).
I only had problems recently with Vista64 and Firefox 3.5.3.
However, I've sorted the crashing (Standard FF "unexpected error" crash) by disabling the flash plugin (Shockwave Flash 10.0.32.18).
I still get some errors though (which just require a refresh or two).
All other websites appear fine... it's very confusing.

The Guardian was hacked recently. The slowdown may in some way be as a result of that.

This has been a problem for me since I got vista and FF3.5.3, so for the past few weeks.
I've seen quite a few complaints about FF 3.5.3 though, so perhaps Mozilla have changed something? Some people do think it's a Flash issue though.
Not sure when there's going to be updates for either.

Recently there have been times when Firefox has seemed quite slow. Other times it has been fine. I'm not sure what's causing it. If the problem is with Firefox I hope they have it fixed soon.
However, Adobe have recently changed their web content delivery platform to one that requires a downloader plugin. Given Adobe's own hit and miss history with creating such things it may also be their doing.

Do you happen to have the download manager Flashget installed? I was having major flash based issues recently when a mouseover action caused IE to crash every single time.
I spent weeks trying to update flash and shockwave and nearly reinstalled the browser before I googled the getflash.dll that was the source of the error and found it to be a part of flashget rather than the "Don't have flash? Download it here" thing I assumed it was.

No flashget. I also saw a bit about that, but I don't use a download manager.
The Adobe web content thing might be the cause, I suppose.
I am wondering about getting an older version of FF, like the one I was using two months ago (FF 3.1.15).

Test the same site in IE and see if it crashes the same way. IE's crash reports are usually a bit more informative (though I've not used FF in a fair while)