Write Post area does not display correctly

I have a few WP 2.0 installations but problems with only one.

In the Write Post area of the faulty blog, nothing appears below the post composition input box. The upload, Optional Excerpt, trackback, custom field and ‘WordPress bookmarklet’ areas do not appear.

Also, the + or – symbols do not appear in the ‘Discussion,’ ‘Password Protect Post’ or other buttons in the right-hand sidebar.

In the blogs which are working, the cursor turns into a 4-pointed cross when mouseovering the radio buttons. It does not do so on the faulty page.

I found when comparing the ‘view source’ view of a working edit page vs. the problem page that the code in the faulty one is truncated.

I have tried renaming my existing wp-admin folder as old_wp_wdmin and re-uploaded all the files in wp-admin. No change.

Please help; I don’t speak php very well.

thanks 🙂