[Plugin: W3 Total Cache] uncached persistent objects

Here are the general debug stats:
Engine: apc
Caching: enabled
Total calls: 3057
Cache hits: 2563
Cache misses: 494
Total time: 0.0601
This is warm cache after a bit of browsing and hitting that same page many times.
There seems to be, to my humble eyes, a high level of uncached objects. Now this may be because of my configurations (defaults) or something else perhaps. But I see that most (but not all) of the source: persistent objects are not cached example:
# | Status | Source | Data size (b) | Query time (s) | ID:Group
1 | not cached | persistent | 0 | 0.0001 | current_site:site-options
2 | not cached | persistent | 0 | 0 | 1:site_name:site-options
3 | not cached | persistent | 0 | 0 | current_blog_libdev.ca:site-options
4 | not cached | persistent | 0 | 0 | 2f62c95411244c91f75ab49cc9434b91:blog-lookup

it seems that it is alot of objects with a size of 0. Perhaps there is a check of 0 == false that could be converted to 0=== false to speed things up? Of course these are just my speculations and I could just be way off. I believe apc_fetch has a param by reference that returns if it was a successful value return (to determine the difference between retrieving the value false from the cache and not being able to retrieve anything).

Thank you,

-Stéphane

http://wordpress.org/extend/plugins/w3-total-cache/