Fireman- you can PM during "Happy Hour" which is described in FAQ of terms of service.
What is happy hour and when is it?
Happy Hour is a one-hour block where everybody has the premium features enabled for them. You can do full-text searches, send private messages, read 100's of messages in one click, etc. All the groovy extras! Everything you see on the Feature Matrix. Happy Hour is every Friday, from 4-5pm EST.