While Sky+ works well most of the time, I have found a bug in the software when faced with a dual recording.
Normally if you have a concurrent recording set for channels A and B but are watching channel C, the box will pop up with a message saying that you have to cancel a recording to continue watching channel C – fair enough as it needs both tuners to do the recording. If you do not respond to the pop-up it will assume you are not there and record both programs, switching away from channel C.
Having two young daughters, Sky is often still tuned to CBeebies when they go to bed. CBeebies closes down at 7pm. If Sky+ now has two recordings set it still displays the pop-up but doesn’t time out meaning that one of the recordings fails unless you come back, switch the TV on, see the pop-up and respond to it, which normally results in missing the start of the one of the recordings.
It would seem that if the channel C in the example above is a channel which is not currently broadcasting, Sky+ fails to time out and you lose one of your recordings.