Support » Fixing WordPress » Moved to new host, themes won’t work » Reply To: Moved to new host, themes won’t work

Seen that happen when the Blog and WordPress URLS in Settings->General are not correct.

If necessary consider using phpMyAdmin to make sure your wp_options table has the correct values in siteurl and home.

siteurl is your WordPress address (URL) and home is your Blog Address (URL).

Update your permalinks.

And, some other info:
http://www.tamba2.org.uk/wordpress/site-url/