Unfortunately, the MacAlly ICEKey USB Slim Keyboard and the IOGear MiniView Micro USB Plus (GCS632U) KVMP switch cannot work together to give you the full functionality of the keyboard.
If you want to use this keyboard with this switch, you have to live with the fact that your volume and eject keys will never work on the keyboard.
There is a method of emulating the special keys using combinations like pressing and releasing "control" and then pressing and releasing "1".
Interestingly enough, the MacAlly iKeySlim keyboard works great with this KVMP switch. Additionally, while the ICEKey requires driver installation, the iKeySlim does not.
So, there you have it. You've been warned.
NOTE: You may have some luck with this tip I found on macosxhints, but I didn't. Let me know if you get something figured out.