I find from my experience that while it is possible to record two streams from 28.2 in the Dreambox, the Dreambox will only decode one at a time if both streams are encrypted.
So in my case with my Irish card I can quite happily record say RTÉ One (encrypted) and BBC 1 London (FTA). I can't record RTÉ One and
Sky1 together. The dreambox will only decode one
Sky channel at a time. The second or later recording is blank.