HTTP redirects, Location: header, and IE5 problems

I have been frustrated recently working with IE5.01+ and HTTP redirects. In PHP, these are most easily done with the header("Location: $url"); call, which magically updates the HTTP return code and everything. :-) So the problem is that Internet Explorer v. 5 and above are just returning Error - Page Not Found when given data like this. What is going on? At present, it looks to me like the problem is that IE5.01 and IE5.5 are set to default not to honor the HTTP/1.0 spec, and take absolute URLs in the Location header. Instead, they display an error. If they are given a *relative* URL, then they are OK. Can anyone confirm this as a general observation, or even more specifically? Can IE5 be set not to ignore the specification for HTTP headers? I have observed this broken behavior with IE5.5 on two other sites besides those of mine which try to do redirects. One looks like it uses Python to issue redirects and the other uses Perl, so I think this is an issue with Explorer. As a workaround, Netscape seems to accept relative paths in the Location header, so that is the indicated thing. (I guess if you want to do off-site redirects, you have to find some other mechanism. Perhaps the HTTP/1.1 Content-location header? I'm not sure...) -Greg Billock