I just bought a 21.5" iMac (2010 version) and wanted to connect it to my Logitech Dinovo Mac Edition Keyboard but it did not seem to recognize it. The keyboard uses a mini USB receiver which I plugged to the iMac and turned the keyboard on. Nothing. I tested the keyboard with my Windows XP -laptop and it immediately worked. I downloaded and installed the newest Logitech Control Center but that did not help either. However, for some reason the keyboard started to work all of a sudden. Then, when I plugged a USB memory stick to the iMac it again stopped working and wasn't recognized by the iMac. I can get it working again if I move the USB receiver to another USB slot. What do you think is the problem here? It's pretty strange that first the iMac acts like the USB receiver is broken or something (by not even recognizing it) and then it starts to work. I know Logitech software usually sucks but this keyboard should work even without it -- and it didn't.