Blogging Roller

I logged into the FreeRoller server for the first time in long time and, on a hunch, I started investigating the OSCache configuration. Turned out, the disk cache directory did not exist. I created the directory and gave it the right write permissions, but OSCache is still not using the disk cache. I'm not sure why. I turned on DEBUG logging for OSCache and I saw the message below, so OSCache clearly knows the location of the cache directory. These settings were good enough for OSCache 1.7.5. What's the deal with 2.0?

INFO HttpProcessor[80][2] com.opensymphony.oscache.base.Config - Properties { 
   cache.debug=false, 
   cache.path=/sites/hosted/freeroller/cache,
   cache.unlimited_disk=false, 
   cache.capacity=600, 
   cache.memory=true
}

I'd like to set cache.unlimited_disk=true and then use a cron job to clear the cache every night, but right now I just want to get the disk cache working. Any ideas?