Anyone know how to change the tablet picture in the start menu if you have cell modem ui installed?

I tried using the same approach to changing the other start menu files:

- put a 48x48 file in hildon folder,
- put the name of that file in the relevant part of the systemui.xml file in etc/systemui.

The systemui.file does not have a section for cell modem but there is a cell modem file in etc/systemui. The etc/systemui folder does contact a separate cell modem file. In that file there are about four of five icon files. Not sure what they are about but I replaced all of them with the name of the file I want to use and now I am left with a blank image.