hash (UK, Ireland?) == pound key (American). We don't call it the pound key in UK/Ireland because we have a currency called that and it would get confusing (Euro now in Ireland).
Keyboards are different depending on the country that you are in. In the UK, the shift-3 key returns £. The # character can vary. Because it depends upon the country local settings that you install with the OS, the esc-char that each key returns on the keyboard can be OS dependant.
I can only assume that lilbandit cannot find the key combination to return the # symbol. I have had this problem in the past, though not on OS X>
Lilbandit - make sure that you have setup your keyboard settings correctly. I remember doing it as when installing OS X, but I cannot remember how - can anyone shed any light on checking/changing the keyboard settings? (I am at work in NT)
R.