I tried to install a game this evening, I was told I didn't have enough storage space free. I have 9GB free (on my 16GB phone), 2.5GB of apps, 181MB of photos and videos, 1GB of misc files, and 1GB free. That just doesn't add up, I should have at least 5GB free. Any ideas what's going on?

Storage analyser tells me I have 8GB free, but doesn't really tell me anything else useful.