You need to expect additional log entries which just have "Informational" character. In the case of APC you can ignore this Info entries for the occ command (cli in your logs) as well as for cron. Those shouldn't use APC.
If APC is not working for you you would get a warning in your admin backend.
To sum-up:
Update to at least 9.0.5
Set loglevel in your config.php to the default value 2
The second points is also explained extensively at the following FAQ: