Mysql binlogs exists, show binary logs is empty
You may need to try something a little unorthodox
service mysql stop

Open mysql-bin.index in vi
Change the contents to this
./mysql-bin.000313
./mysql-bin.000314
./mysql-bin.000315

Save mysql-bin.index
service mysql start

Login to MySQL and run
SHOW BINARY LOGS;
SHOW MASTER STATUS;

This stunt worked a few times for me.
Give it a Try !!!