1x4 KVM Switch Detecting Keyboard/Trackball Combo

[Lenxe]

Hi

I'm using a HP 1x4 KVM switch and cherry keyboard and trackball combined, this connects to the KVM switch using a single usb.  The problem I am having is that the servers connected don't recognise either the keyboard or trackball. I have also tried using the KVM keyboard commands (e.g. ctrl + ctrl + # + Enter) and this doesn't function either.

I have used a different sperate keyboard and mouse, these both function correctly with the servers and with KVM switch commands.

I connected the cherry Keyboard and Trackball via the usb hub on the front of the switch, this functions as expected regarding the operation of the servers. 

My educated guess is that the switch does not like having the combined keyboard and mouse signal through a single usb connection. Can anyone comfirm this or offer any information. This would be much appreciated.

Thanks in advance. 

Lewis

I have the following hardware 

4 x ProLiant DL360 G7 servers 

1 x HP 1x4 USB/PS2 KVM Console Switch (AF611A)

1 x Cherry ML4400 USB Compact-Keyboard with Trackball