Playback cuts out when switching to another window

Hi, can anyone help me?
This is another one of those annoying things that I know I’ve come across before and just can’t for the life of me remember where; even more annoying, it didn’t seem to happen when I last used Cubase before Christmas, but has started to happen now.
I’m not sure if this is two separate problems or different aspects of the same one, but: in Cubase 5, if you’re playing back a song and you then switch to another window whilst still in playback, the sound cuts out until you return to Cubase. The other problem occurs if you’ve got Cubase open but then attempt to play back another file using, say, Windows Media Player: Cubase will ‘hog’ the soundcard until you shut it down, whereupon WMP will then work.
I don’t know why this has just started to happen, seemingly of it’s own accord; the only thing that’s different is that I’ve just started a new project rather than continuing work on an existing one ( which would have been the case before Christmas ). I thought there was a radio-button option somewhere in ‘preferences’ which covered this ( something along the lines of ‘release soundcard’ or thereabouts, although I’m not sure if this solves both of the above problems or only one of them ); as I say, for the life of me I can’t seem to find any such option in ‘preferences’, which makes me wonder if I’m looking in the wrong place?
As always, any help would be appreciated.

A part of your problem must be this switch,

Release Driver when Application is in Background

And another, Cubase hogs the soundcard, perhaps is the soundcard related. It depends on which audio interface you are using, some does not allow multiple clients to be used at a time and some do.

The ‘release driver’ thing does sound like what I was thinking of, but I can’t find that anywhere under ‘preferences’ … also not sure why it would have arbitrarily switched itself on ( or off ) over Christmas …?! The ASIO driver is exactly as it was pre-Christmas and still seems to be working the same in every other respect …

Not sure what happened to you during Christmas but the switch always had been there in the audio setup not in the preference which is settings for the software side and the setup pages are for hardware.

Thank you, with a little bit of searching in the audio setup menu I found it, and that appears to have solved the problem.