Multiviews and GET requests no longer working?

Hi all, So a few weeks back on my Debian Sid box I had everything running nicely, PHP4, Apache 1.3, and had it such that Multiviews were turned on, and I could call /foo?id=1 and the file foo.php would register the variable id as having a value of 1. I dist-upgraded last weekend (now PHP-4.1.0-RC2), and now it's stopped working. If I call foo?id=1, not only is the id variable not set, _SERVER[QUERY_STRING] isn't either. Cookies and session variables work fine, it's just variables passed via GET. If I turn off Multiviews, the variables come through fine, but it means calling foo.php. This has completely floored me. I don't want to re-write the site with references to URLs with file extensions -- I deliberately don't want users to see file extensions. Anyone had similar problems? Anyone have any ideas what to try? I have register_globals = On in the php.ini file, nothing in the php.ini or httpd.conf files appears to have changed. I'm at a loss. Please help! Thanks, James Green