No sound from MIDI controller

Hi, something odd has been happening with my MIDI controller (an M-Audio Oxygen 49). Without me changing any settings, yesterday my controller stopped working in Cubase6. It was still being detected, there was just no signal. Strangely, when I open it in Studio 5, it works fine, and then if I open it in Cubase 6 straight afterwards, it works too - but if I close everything and leave it for a while, then it won’t work in 6 again. So now to use my MIDI controller, I need first to open Studio 5, close it, then open Cubase 6. Anyone have any idea what might be happening here?

Windows 7 Home Premium
Service Pack 1
Pentium Dual Core 2.00 GHz
3 Gb Ram

I’ve had this, if you go to device setup and then midi port setup, deselect the midi keyboard in the “in all midi” column on the right and then reselect it and click OK it should work again, I’ve only had trouble with a Carillon keyboard but this is just a re-badged oxygen 49, as you say no probs with Cubase 5.

Thanks, that helped. I still have to do it every time, but it’s much better than opening Studio 5 then closing it every time!