Not able to send private messages

invalid@example.com (BrianBoston), BrianBoston
Wed, 14 Dec 2011 13:21:54 +0000

Wasn't sure where to post this.
Brand new to the forum and I noticed that I m not able to send private messages. i keep getting a "this action cannot be performed".
Anyone know why?
Thanks for your help in advance

[Post title edited - Admin]