hydn, I just tried apc.stat=0 and in effect, caching is ok now. PHP scripts are correctly added to the list now. It seems to be fast but hard to say on my local server. A good test will be on my production server... What about a final version of APC for PHP 5.3 ? ;)
For this test, in my php.ini, I do not add any settings for APC. I use default settings (except extension=php_apc.dll).
For information, actually on my production server, I use eAccelerator (from sitebuddy.com) with PHP 5.2.9 TS and it is very fast. Before migrating to PHP 5.3, I wait eA 0.9.6 binaries to see if it runs better than this APC release.