Smoothwall Express 3 refusing connections

Been running SWE3 fine for the past 2 years. Suddenly this morning get a call to say students (who go via this proxy) have no internet; staff internet which doesn't go via SWE3 is fine.

Login to admin interface, everything seems ok. As we use dansguardian mod I restarted this - still nothing. Reboot the SWE3 box - nothing. Do a shutdown for a few mins and boot back up - nothing. Worth noting it pings fine and can login to admin interface fine, but when you try to browse to a page is seems to be refusing and/or cancelling the requests. Config hasn't changed.

What is more bizarre is that I managed to get a connection to bbc.co.uk but one where only the text is showing (like it has started downloading the content, stopped then just displayed what it got - see attachment). This is up to date. Normally though it just says connection refused.

Help or advice much appreciated!

Run "top" - is anything eating all your CPU time?

Sounds like it could be a hardware issue though.

Trafficlogger is using less than 10% - the rest negligable amounts. When you say hardware - any component in particular likely to be the culprit (RAM, NIC etc)?

I have had a similar issue before but the proxy stops letting requests through, then i try rebooting the host and loose all connections and the only way to get it back up is to locally log in and run setup as root and play with the settings. Weird, i know but it has worked fine for me in the past.

Also have you tried clearing the cache and restarting the proxy directly after?

I always like hard disks as a scapegoat :-/

Trafficlogger is a bit heavy, so that's normal. Is squid running OK?

Cache cleared countless times and I even uninstalled advanced proxy mod and used the vanilla one with no luck. Reinstalled advanced proxy and no different. However, I noticed something. When checking the uptime of the services, the "web proxy" service stops then starts each time a page is browsed to/refreshed. I browse to a page, immediately check service status on the admin interface and it stops. Refresh again and uptime resets - so it is restarting the proxy service each time a page is browsed to.
I tried changing the RAM in case that was at fault but it's fine. I'll try running through setup again and see what that does.

Running setup makes no difference unfortunately :(

[edit]Also it seems if I refresh too much or browse to too many pages the web proxy service dies and won't restart (even if pressing save on the config page).[/edit]