I use firefox up to date, once in a blue moon I will have some trouble, and I think I have double posted from it a couple times. It's usually just a hang in the communication between my computer and the forum server. Not a big deal, and probably not even local to either machine, but somewhere in between. Do you run internet security scanners on your computer and keep it cleaned up? I recommend Ccleaner, spybot S&D, and SpywareBlaster. The latter of the three is not a scanner but is great at preventing problems.

Those can all be easily found with a google search. Ccleaner is I think still piriform, Spybot is SaferNetworking, and SpywareBlaster I'm not sure who make that. They have all been around for a very long time and have never lost reliability.

Another good program is Malware Bytes. It will find some viruses, worms, and trojans on your system.

These all have free versions available, but will have to be manually run. Spybot has some active protection, but for the most part I don't recommend using it, as that protection tends to hog resources on the computer. Just use the immunize feature and the main scan.

Hope that helps, or that you already know about and use programs such as these lol.