How Do I Fix Pager & Category Navigation?

Hi.

I'm a Drupal newbie having a serious issue with the pager/categories on my site that makes navigating content impossible for users.

The links "http://site/?q=admin/node&from=50" and "http://site/?q=node&page=7" (regardless of the page numbers) return the front page of the site only. PLUS, navigation by category returns 404 errors. All of the content is accessible through the admin pages (if I don't use the pager), though, so I do know that it's there somewhere. Something bad's happening in the query or somewhere in my database, I suspect, but I have no idea how to fix it.

Here's some details of the site that may be relevant:

1) I recently installed Drupal 4.6.4 at a new server and imported my blog content from my old site, which runs WordPress 1.5. I used Sam Revitch's Script to perform the export/import. It seems to have worked well, and all my content - posts, content, dates, etc. - shows up sorted and intact.

2) My Drupal site is not readily accessible (DNS not transferred yet from old site), so I access all the content and admin stuff through a mirror. Everything works well (I can admin, post new content, theme, etc.) except the paging and category navigation.

Also, FYI, any new posts I make to the Drupal site, while they are posting and displaying properly, are equally unnavigable.

Thanks to anyone who can help me with my troubles -- I'm loving Drupal so far, and if I can fix this, I can transfer the DNS and finally get the site happening!