Apparently it was a cargo smoke detector sensor failure leading to a false alarm. According to the local daily papers (if they are to be trusted), the required part was sent from nairobi the next day. It was installed but the Greek CAA would not issue a permit for them to depart because they needed to do an airworthiness flight test first (or something). That was the reason for all the delays. Eventually the governments got involved and they were given clearance to leave. The aircraft involved is already back in scheduled service