I'm Away message failures

I have noticed for some time that my "I'm Away" message fails to load and send frequently, even though "I'm Away" is checked and set in status. I first noticed it in v3.6.6, but can't say when it started. Someone will connect and I expect the away message to send, but the message isn't queued. There must be some condition I am missing? When it fails the connection times out or the other party is left going "Hello, hello ... how are you? Are you there?".