Post installation

I am finding alot of support needed for people having the "You are not authorized to access this page" error when an anonymous user accesses a page. The problem is that it is occuring randomly without warning. I am using the category module. Everything will be working fine, I am adding categories or containers, then all of a sudden the anonymous user is not authorized to access the page. I am using drupal 4.7 and have checked the following:

Full error message:

mb_ereg(): mbregex compile err: invalid regular expression in /home/username/public_html/modules/user.module on line 217

This seems to be the only casualty of a move from one host to another, plus a CivicSpace upgrade to 4.6.8. Chances are something didn't get moved over quite right, my uploads were frequently interrupted on the host side. The error appears when the user module is asked to create or modify a new account. It doesn't seem to interfere with the operation.

I have set the email setting in settings.php, but the contact form only sends emails some of the times. The create new account however, works perfectly. What could be the reason, help please.

I recently received this error message:

Unable to connect to database server

This either means that the username and password information in your settings.php file is incorrect or we can't contact the MySQL database server. This could mean your hosting provider's database server is down.

The MySQL error was: Access denied for user: 'root@localhost' (Using password: YES).

Currently, the username is root and the database server is localhost.
...

Here is why I posted in Post Installation: This error happened some weeks after I had installed and had a successfull go of it. I had added lots of content, etc.

This error suddenly appeared without warning one day when I went to the site, and where a few days before it was working.

Sorry all, may seem like a simple question, but...

I want to call the 'taxonomy_autocomplete()' in a text field in a CCK node.

where exactly do i put the php code?

j

How am I able to setup standard forum behavior of automatically sending a "new reply notification" email to users who've posted in a forum thread, each time a reply is posted?

I noticed the Subscription module, though apparently this doesn't automatically setup subscriptions unless the users have activated it in their profile.