Problems after changing install directory

Hi. I had my WP installed in a directory named wordpress/ but I just renamed the directory to blog/ instead. The main page and the Pages work fine, but if I try to access individual posts (either by category or date or whatever) it gives me this error:

Not Found
The requested URL /wordpress/index.php was not found on this server.

I don’t have a wordpress/ directory anymore, nor do I have any mention of a wordpress directory in any of the Options. One more thing, if I disable the Permalinks, it works fine; only when I enable the easy-to-read Permalinks do I have this problem.

Can anyone help me out?

Thanks,
Amir