Ok, this is a tricky one...

I had this weird problem where my browser (IE5.5 & IE6) went into a crazy fit and was refreshing like mad, cpu usage went up to 100% until I hit stop.

I could never figure it out, so I ignored it.

I got the same thing again today. I've got Apache & PHP running on my laptop (Win XP Pro), and although it worked fine locally, when someone accessed it, they got the mad refreshing loop (only in IE).

I've been messing about all afternoon with telnet logs and such, and I fixed it...

I set the output buffer to On and it went away. This is not a fluke, loads of people had the problem, now none of them do it.

You won't be able to reproduce it, so if you drop me an email, I'll turn buffering off and send you an url to see it.

I'm not sure if it's an IE thing, or a PHP thing, but since buffering solves it, I'm looking towards PHP.

I've got telnet logs of when it happened, and when it didn't (they're a big long to paste here) which I can supply if needed (both almost identicle)

If someone emails me when they're online, I'll turn buffering off and let them try it (provided I'm at home when they mail)