I'm trying to optimize APC for my Amazon EC2 Micro server running one Wordpress-site with W3TC. I've started with the settings advised by TechZilla in another topic but I keep getting high fragmentation with 50% of space being free.

I've uploaded an image to http://www.maartenprovo.be/downloads/apc.jpg but I can't post it here since I need at least 10 reputation.

What values can I optimize to prevent fragmentation?

[apc]
apc.enabled=1
apc.shm_segments=1

;32M per WordPress install
apc.shm_size=164M

;Leave at 2M or lower. WordPress does't have any file sizes close to 2M
apc.max_file_size=2M

;Relative to the number of cached files
apc.num_files_hint=1000

;Relative to the size of WordPress
apc.user_entries_hint=4096

;The number of seconds a cache entry is allowed to idle in a slot before APC dumps the cache
apc.ttl=7200
apc.user_ttl=7200
apc.gc_ttl=3600

;Auto update chache files on change in WP-ADMIN or W3TC
apc.stat=1

;This MUST be 0, WP can have errors otherwise!
apc.include_once_override=0

;Only set to 1 while debugging
apc.enable_cli=0

;Allow 2 seconds after a file is created before it is cached to prevent users from seeing half-written/weird pages
apc.file_update_protection=2

;Ignore files
apc.filters

apc.slam_defense = 0
apc.write_lock = 1

apc.cache_by_default=1
apc.use_request_time=1
apc.mmap_file_mask=/var/tmp/apc.XXXXXX
apc.stat_ctime=0
apc.canonicalize=1
apc.write_lock=1
apc.report_autofilter=0
apc.rfc1867=0
apc.rfc1867_prefix =upload_
apc.rfc1867_name=APC_UPLOAD_PROGRESS
apc.rfc1867_freq=0
apc.rfc1867_ttl=3600
apc.lazy_classes=0
apc.lazy_functions=0