Introduction requests/responses never get ACKed

It looks like that in private conversations all messages except actual private messages, never get ACKed. There is only ever one checkbox for forum/blog and introduction messages even if the message has been delivered on the other end. Leaving and re-entering the conversation doesn't help.

01-03 16:36:03.864 I/DuplexOutgoingSession: Generated ack: true
01-03 16:36:03.864 I/DuplexOutgoingSession: Sent ack
01-03 16:36:03.914 I/DuplexOutgoingSession: Generated ack: false
01-03 16:36:03.964 I/DuplexOutgoingSession: Generated ack: false
01-03 16:36:04.024 I/DuplexOutgoingSession: Generated ack: false
01-03 16:36:04.024 I/DuplexOutgoingSession: Generated ack: false
01-03 16:36:04.404 I/DuplexOutgoingSession: Generated ack: false
01-03 16:36:04.444 I/DuplexOutgoingSession: Generated ack: false
01-03 16:36:04.504 I/DuplexOutgoingSession: Generated ack: false
01-03 16:36:04.504 I/DuplexOutgoingSession: Generated ack: false
01-03 16:36:04.504 I/DuplexOutgoingSession: Generated ack: false
01-03 16:36:04.504 I/DuplexOutgoingSession: Generated ack: false
01-03 16:36:04.504 I/DuplexOutgoingSession: Generated ack: false
01-03 16:36:04.504 I/DuplexOutgoingSession: Generated ack: false
01-03 16:36:04.514 I/DuplexOutgoingSession: Generated ack: false
01-03 16:36:04.514 I/DuplexOutgoingSession: Generated ack: false
01-03 16:36:04.514 I/DuplexOutgoingSession: Generated ack: false
01-03 16:36:04.514 I/DuplexOutgoingSession: Generated ack: false
01-03 16:36:04.964 I/ConversationActivity: Messages sent
01-03 16:36:04.964 I/DuplexOutgoingSession: Generated batch: true
01-03 16:36:04.984 I/DuplexOutgoingSession: Sent batch
01-03 16:36:05.454 I/DuplexOutgoingSession: Generated batch: false
01-03 16:36:05.994 I/ConversationActivity: Messages acked