i was wondering can any of you guys help?

every time i go to print a statement of account i put in the dates ok but the date come up 30/12/1899 when i go to try and print them off so they wont allow it as its over a hundred years out!!very strange!!
it used to work ok.i have a few accounts that owe 3 cleans and i usually print a statement of account and leave a SAE so they can send a cheque.im baffled by it.
im sure its since i updated george and i also lost the pound signs which is not too much of a problem but this is doing my head in!
thanks in advance
dazmond