how to ban user agents

I’m trying to ban a number of user agents, but they seem to be getting through any way. For example, in the Ban User Agents section of the Ban Users page, I’ve entered:

Baidu
Baiduspider

In htaccess, the result looks like this:

RewriteCond %{HTTP_USER_AGENT} ^Baidu [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^Baiduspider [NC,OR]

But in my most recent logs, I see:

User Agent: Mozilla/5.0 (compatible; Baiduspider/2.0; +http://www.baidu.com/search/spider.html)

Do I need to enter the full Baiduspider/2.0, or is this feature not working correctly? It’s happening with a bunch of other entries/agents, too.

http://wordpress.org/plugins/better-wp-security/