baataboom on "mod_rewrite is enabled but zp says it is not"

I've just installed zp 1.4.12 on apache 2.4 (Solaris 11). Everything except mod_rewrite appears to be fine. Apache has mod_rewrite loaded (apachectl -M, and phpinfo() and apache_get_modules() confirm this). But zp indicates that mod_rewrite is not loaded.

Permissions on /<zp_base_dir>/.htaccess are 444. I have not made any changes to the <zp_base_dir>/.htaccess file.
And in the httpd.conf I changed AllowOverride to All (from None). (I thought this last action might have solved it).

Given the above, zp still declares that 'Setup did not detect a working mod_rewrite facility' in Admin|Options|General|URL options.

Can someone point me to a solution?
Thanks