registration flood after installation

I’ve been flooded with registrations mostly from “hotmail.com” addies since we got this plugin working so I just wondered if there’s something wrong? spam is more than ever even though akismet is enabled. I’m not talking 10-20 I mean 1-200!
If you can think of or do anything I’d appreciate it.

Andy

http://wordpress.org/extend/plugins/facebookall/