Bluetooth Keyboard?

Hi.
I don't think this got through, but I did just try to post this previously,
so if it shows up twice, sorry.

I have just got hold of a Logitech bluetooth keyboard and mouse, I think
it's the MX-900. I got both pieces paired and connected to my pc fine, but
now, after a reboot, only the mouse works, the keyboard is disconnected. I
can pair and unpair the keyboard, so it must be working okay, otherwise I
wouldn't be able to enter the PIN code as part of the pairing process; but I
cannot get it to connect. Like I say, the mouse works fine, but the
keyboard won't. Whenever I try and connect, it just says that the keyboard
has to be in Discoverable Mode for the process to work. What's discoverable
mode and does anyone know why my keyboard mightent be in it? I know the
batteries are fine, because I was able to enter the PIN when pairing. If I
simply uninstall and reinstall the software, do you think I could start
afresh, or would registry keys etc mean I'd end up at the same point pretty
quickly? Any thoughts welcome. Thanks