When a channel is automatically updated, the channel name may change. In the case of ITV HD, it may revert to a number (10510).
This may be done to 'disguise' the actual name in non-Freesat boxes, although I've only come across it in the Passion.
You can change the name manually to ITV HD, whether it will stay so permanently I don't know, that pid number is burnt into my brain since I started playing around with ITV HD, so it doesn't worry me
Don't know about random characters or Lux TV, may be a clean install of the software might help.
Llew