T50 FormURL parameter not working.

does anyone know the settings for a customized logo for the login box? per the admin guide, it states this must be a .png file 100w x120h. this seems a bit odd, as the size looks more like the file i use in wnos, which is 352w x 80h. also the older versions
I have created one (100x120), and placed in the wlx/bitmap folder, but my thins are not recognizing and still using the default wyse logo.

Any help would be appreciated!