Sorry, I did not realize you started out by specifying the device type when the Icon Dimmer was initially added. I added an Insteon address that did not exist (in case of comm problems) and added a new Icon Dimmer, neither of which changed the device type to OTHER. I need to step back and get some basics.
What EZServe firmware are you running? 2.6.16 is the latest.
Are you using the HTML interface or the Harmony Client (Adobe Flash)?
Are there any error messages, error popups, etc that display during the device add process?