Will do in future - wasn't sure if this was related to the message on the inbox page that was there for a few days hence why I didn't report it straight away.
Reply status now works for new replies but seems that any message replied to historically from any time before today has lost it's status and not just the ones that have been replied to in the last few days.
I can live with it though as now message history is back the last few days and now has the correct dates
