Have looked at the instructions in this thread but so far with no luck. I don't seem to get the option to type anything into the inbox pop up when it appears. Clicking on a person's avatar as described above is no better. Is this because I am a relatively new and inactive member so far or am I missing something?
It's part of our anti-spam measures - we don't allow brand new members to start conversations. You can received them, but sending will kick in once you've got a few more posts under your belt.