OK, so, I am facing a prob not unknown, I had faced it on my first gen iPod as well.
Thing is, every theme I download, gets applied ok, but the Weather icon simply does not change. I have no relating package installed from cydia, my phone language is english, I double checked the files, theres a Weather.png in every theme folder, I even tried a clean install and still this damn icon will not change.
Has anybody faced this problem?