Windows 7 - Tuner not available

I have a number of tuner cards in my machine. A Hauppague one, a Videomate one and a Cinergy 2400i DT card. Windows 7 has been running OK for a couple of years now. Not much software over and above the OS has been installed to keep the system as clean as possible. Occasionally, I have had the 'tuner not available' type error message (particularly on BBC - I am in Oxford, UK), but have managed to get it going again by playing back something that I had previously recorded then going back to the TV channel (BBC 1 for example) and for some reason, this seems to kick it into working again.


The problem has been getting much worse over the last few weeks. Now the above 'solution' (i.e. playing something previously recorded and then returning to live tv) doesn't work. Google searching led me to try closing MC and restarting the Windows Media Centre Receiver service, then restart MC. This seemed to work. But now, this isn't always a solution. I did more Google searching and found a suggestion that it often happens when the machine has gone to sleep and then has woken up automatically (to record a programme for instance). A solution was to manually put the machine to sleep and then wake it up. This seemed to have worked this morning for me!


However, problems still persist, and the manual sleep/wake procedure doesn't always work. There are 4x tuners in the machine, and I am rarely, if ever, using more than perhaps 2 (or sometimes 3) of them. I should never run out of tuners. However, I often get a message saying 'no tuner available' when another channel is set to start recording!


This is a deeply frustrating set of problems that in all my searching I have not managed to find a true solution for. It seems I am not alone with these sorts of problems.

What is causing it?

My machine is a 3-core AMD Phenom with 4GB ram. All drivers are up-to-date and latest windows updates are installed. There are no explamation marks in Device Manager and everything else seems to be functioning well and normally. Windows media centre is a great bit of software and allows me to have all my music, photos and videos in one central, easily accessible place, but the 'TV tuner not available' problems are really making me rethink how I do things. I am not really sure if there is a good alternative out there.

Please help.

Thankyou.