problem with multiple cookies, PHP, and proxypass under apache

Hi, I have an apache server which is configured to pass some requests through to a secondary, chrooted apache server. For each virtual domain that passes through, I have an entry in httpd.conf which looks like :

  ProxyPass         / http://domain.hosted.mydomain.com/

ProxyPassReverse / http://domain.hosted.mydomain.com/ Now, everything runs fine in the secondary server, which has an identical config to the first apart from being chrooted. (Identical means that a diff of the two config files shows paths only). However, when a PHP page on the secure server creates more than one cookie and attempts to pass it back through the proxy to the client, it doesn't appear. On the possibility that it might be a browser issue, I grabbed the raw return data, and in fact, there is only one cookie header returned. No matter how many cookies I create in PHP, whether multidimensional or of different names, only the very last one returns to the client. If anyone can shed light on this problem, I'd be very grateful. The full system config is :

    Linux 2.2.19, uniprocessor
    Apache 1.3.24
    PHP 4.2

Regards, Vincent