An example from this afternoon - EXS714 was in MyFlights, coming from Belfast, so was almost certainly on the network previously. No route was showing on the grid (or map).
In the Routes table, it had valid route info (EGAA to EGNH). I did notice that the CH field started with 200808. I deleted this date, and then turned off hardware flights for a minute. Restarted them, still no route shown.
I then went back to the routes table and copied a date starting 200906 into the CH field of EXS714. Again turned off hardware flights, waited for a minute, turned on haredware flights, and the route appeared on the grid.
So it appears to be a problem with it not updating old dated records, possibly.
I'll look for more examples.
Rod