HTML5 manifest and chrome
if you just want to change the size of your cache, start chrome with "--disk-cache-size=N".
If you want to see whats in your cache, just type about:cache or about:appcache-internals in the Omnibar.
For a reference file: DOMApplicationCache Class Reference or google "A Beginner's Guide to Using the Application Cache" (I may not post more links, I'm sorry)
The error can also occur when your system drive is running low on disk space, so freeing up disk space can resolve this in this situation.