Mokita - 10:18 am on Mar 23, 2011 (gmt 0)

Hi Jim,

Sorry about the delayed reply, I've been away.

Many thanks - you've solved it for me. The misbehaving rewrite rules did not have ErrorDocuments excluded.

Those rules worked for years on the old server, so I didn't realise they needed to be.

Also, I don't use a custom 500 error doc, and the paths to the 4xx ones were exactly as you say they should be.

With regard to accessing the Error Log file - we have cPanel which does show most errors for a short while. But the Log details I quoted above, came from the full actual (shared) server log that is only accessible to our host. I don't think there is any Host that allows access to those.

And interestingly the cPanel Error Log, did not show anything at all when the looping 403 turned into a 500 error. That was another thing that added to my confusion.

Thanks again for your help - much appreciated!