Can't seem to add new fields to a content type

There are a few things that can cause this, and most of them are related, one way or another, to permissions. If you are logged in as user/1 (the root administrative user) and can't see the fields, then you have a different problem.

Assuming that you are not, then you should check to make sure that you have not assigned an input filter to your field that is not available to your users. You should also check the content type field management settings -- admin/content/node-type/your-content-type/fields/field_your-field-name -- to make sure that you haven't inadvertently made your field inaccessible.

There are many other possibilities, particularly if you are using any kind of access control modules or are using a custom or customized theme that might not play by the rules, and if you are using Drupal 5 or lower, all bets are off.

While the folks in Los Angeles are arguably smarter and better looking that anyone else in the Drupal world, you might get a bit faster and more thorough result but casting a broader net when asking a question. I suggest the support forums (http://drupal.org/forum/18) and the #drupal-support forum on IRC (particularly for small-scope questions). There is a support mailing list -- support@drupal.org -- that I don't use, and, for bugs and well defined problems with a module, etc., there are the issue queues.