I guess this is the right place to put this?
I know I'll never get an answer from Coinbase, so I'll ask you guys.
I transfered 1 BTC to GDAX, thinking I might want to sell it at $10,000 (OMG, $10,000!!).  Changed my mind, and I'm going to put it over in coinbase for a day or two.  So anyway, it shows I have exactly 1, but when I go to 'free' transfer to Coinbase, it shows .993xxx BTC max, which is $64 less than a full bitcoin.  Can't figure out why, coinbase transfers should be free.  Guesses?