What kinda specs are you running, can't believe it's the pictures on this forum that's causing the problems. This is how to clean your computer of any crap that's accumulated which should solve any problems:
I'd suggest doing a full virus and malware scan to begin.
Next open add-remove programs, uninstalling everything you don't use (make sure you understand what each one is first) this will help no end. Also delete any files you don't need (from my documents etc.)
Download and run a registry cleaner, this is the most important way of keeping your pc running smoothly.
Lastly defragmenting your hard drive. This will speed things up slightly, keeping all the files in order and easy to find for the os.
edit/ if you need help with any of the steps, just ask.
Ah that's great, I know alot of emphasis is put on Anti-virus and Anti-malware nowerdays, but not all that many people know about cleaning their registry and how much of a difference it actually makes!
It still sounds like something other than the pictures causing you the problems imo. There just isn't that many pictures here on therugbyforum, and to cause something to crash is very odd.
I'm sure you've done this, but just in case....... emtying your temporary internet files, cookies etc. might help.
If you go into My Contols on the top of the page and then in the menu on the left side of the screen click on board settings and there's options to turn off sigs, avatars and no longer view images, I have no sigs and avatars and generally find the forum runs much smoother for me, much less of an eyesore as well, but that's just my personal view