Hash Refinery wallet not in BTC, won't change

[CalDude]

I've just started using Hash Refinery and when I visit their site and type in my BTC address into their wallet, it shows a warning message: "WARNING: Your payout currency is not set to BTC. If this is not what you intended, use 'c=BTC' in the password field of your mining software."  At first, in the username field, I'm using a BTC address and password is x.  The site specifically says that if you're using the default pool your profits will be automatically converted to BTC.  I have since changed my password to -p c=BTC to try and force BTC, but the warning message persists.  My balance shows an unearned balance of APC coin under the BTC address.  I'm worried they're going to send that APC to a BTC address!  What am I doing wrong?  Thanks.