My bet is that you are using the literal "£" character when you should be using the html entity:
£
but lets be realistic; we do not support modifying the currency symbol. This means that when you try it and it doesn't work as you expect, we cannot help you to fix it.
Like MikeH has said in his post, there will be an update available shortly that will address support for the Great British Pound, Canadian Dollar, Australian Dollar and Euro.