Sounds like your STB is struggling to find information. UN400 basically means that it cannot pick up the information on the server, either because it cannot handle the amount of info, or is just incapable of doing so.
SEAC410 means that it cannot find the information for the VOD purchase, as though it is non existent.
Both require a call in to our Faults department, so we can investigate!
---------- Post added at 14:03 ---------- Previous post was at 14:02 ----------
Is the light on the front of the STB flashing by any chance?