I'm guessing that you are using some strange brew CA solution. We change our control words multiple times per minute and our keys are changed mutiple times per day. Your STB must be processing EMMs to see the key changes. It's possible that this processing stops during standby (it's not suppose to) and you have to wait to aquire the most recent keys when the box is turned back on. There would normaly be a significant number of key changes overnight.

So far (fingers crossed), we have not struck a bad smart card - the Irdeto folk have done very well to date. So, whilst it's not impossible that the smart card is bad, it seem very unlikely.

I lived in Hong Kong for many years, and when the new airport opened, we found ourselves ocasionally under the flight path (in Clearwater Bay), the aircraft's downward facing terrain clearance radar would kill our STAR TV reception on a frustratingly regular basis. STAR TV had its head office on the harbour and the incomming ships would wipe out reception as they steamed past. On an analogue signal, this is just some sparkles, on digital it wipes out an entire GOP.

Your issue sseems much more likely to be CA related.

I have no explaination for the Bloomberg effect (cue "Twilight Zone" theme music) ??????