I just committed some changes to the CacheBox SVN repository and pushed up a new 0.9.9 version. I realized suddenly that getting the occupancy of a specific agent isn't something I do very much of... but it was part of the CacheBoxAgent.cfc for people who might be interested in getting that metadata in their own apps.
It turns out because it's not something I do very often, that part of the CacheBox framework hadn't been well tested and the agent was attempting to call a method (getAgentSize) that didn't exist in the CacheBoxService.cfc. That lead me down the road of looking at a couple other methods and realizing that CacheBoxStorage.getHeadCount() wasn't being used anywhere and actually was redundant with CacheBoxStorage.getOccupancy() but the getOccupancy() method was missing an argument. D'oh!
Anyway I fixed all this stuff, rolled the version forward to 0.9.9 and unfortunately had to also roll the agent version forward to 1.4. I updated DataFaucet and the onTap framework with the new agent in their SVN repositories, but since those don't actually use the affected feature, I haven't published new archives for them yet.