This problem is because different apps change the size of the right panel, so after investigation, myself and Loonyworld have come to the conclusion that 113x200 pixels is the best size for those images. Obviously these will look clipped in some views, but it stops it being too small in others.
Custom Right Menu Textures
Oh and keep your eyes open as myself and loony are throwing ideas around for the difinative guide for making skins for the 9210.
BTW - TANKERx get in touch and we can use your info in our skinning guide for the skinning of apps and icons etc....