360 Memory

My Samsung TS-360 is 2 months old, bought new. Has been glich free till now. After installation of all available channels (Air, Cable & Digital), I selectively remove the channels I don't want (all Air & Cable) so I am left with strictly HD channels. First up is PBS channels 2-1 & 2-2. There is also 2-104 which is labeled "UpDatTV". Next up is 4-1 (CBS),5-1 (ABC),7-1 (NBC and 25-1 (FOX). These are all OTA.


I can select any of these channels in random or sequential order and I receive all, OK. When I power down the 360 to "Standby", wait about 10 minutes and then power up, channels 2-1 & 2-2 and 2-104 are gone from memory and I have to re-enter them to receive the signal. All other HD channels are fine, still in memory. If I just program 2-1, 2-2 & 2-104 all alone to memory, I don't lose them. Add any other channels and they disappear.


Any thoughts on what is happening here.


Thanks


Chris