Ok, this will sound really dumb, but what file do you use for the icon image when you are creating a new weapon or piece of armor?

http://cs.elderscrolls.com/constwiki/index.php/Paintshop_Pro:_Creating_Inventory_Icons.

Otherwise choose something from Textures\Menus\Icons\xxx\yyy.dds
(xxx = a directory name, yyy = file name)

Usually you would create a new Icon to use with it ! -- but you could use any one of the existing weapon icons if you do not know how to create a new one. (NOte the icons need to be extracted from the BSA file and have to be in the Data\Textures\Menus\Icons\ folder or a sub folder of that folder in order for the CS to be able to select it otherwise you'll get an invalid folder error)

If you need an icon or a few made either send me a copy of the NIF and textures you are using or a screenshot of the new weapon\armor piece in the Nifskope render window (upload the NIf\texture or screenshot to a host and PM me a link) and I can put together a quick icon for you.

Ok, thanks so much!