Custom permalink doesn’t work anymore

Hi All,

I read so many post about this topic, that you could think it’s the same old problem. Welll it may be, but in all the post read, even those one marked as SOLVED, the solution proposed does not apply to one.

In a brief, when using the default value, everything is fine; when I use anyone of the other option I’m not able to access to the pages or post in the database via the slug.
Also, the server does not return the friendly 404, but I got the standard apache 404.

I’m testing everything on MAMP, and everything was working fine until a couple of days ago. I installed a plug in today, which I thought it was the cause, but it’s not because deleting it the situation does not change.
I even tried to download a fresh installation of WP 2.9.2 and 3.0b1 but the problem is the same.

I setup permission for .htaccess to 664 and anything is changed. I paired the local .htaccess with another live WP install and the info are the same, so I imagine a couple of solutions read about conf file permission and missing rewriterule are not correct.

I really do not know what do to.

Any hint?

Thanks
Andrea