htaccess security problem

I have been using the security code from the Digging into WordPress book to help secure my WordPress sites. The last website I used this on my client received this error when accessing the website:

Forbidden

You don’t have permission to access / on this server.

Additionally, a 403 Forbidden error was encountered while trying to use an ErrorDocument to handle the request.

I did some trouble shooting and found that the following code was causing the issue:

# PROTECT SENSITIVE FILES BY FILE TYPE
<FilesMatch "\.(htaccess|htpasswd|ini|php|fla|psd|log)$">
Order Deny,Allow
Deny from all
Allow from 01.234.567.890
</FilesMatch>

I have used this code on several websites and not received this error. Anyone know the cause of this and what I should be using to protect these files?

Thanks!