Upgrading from 2.9.4 to 3.0.x and with a custom theme

Try this simple steps to verify it!

  1. Install WP DB-Backup in your 2.9.4 version.
  2. Backup the DB
  3. Setup a test server with WordPress 3.0.4
  4. Install WP-DB-Backup and restore from your previous backup
  5. Test your theme