Some of the entries in your list refer a chrome extension (which are typically not loaded in incognito mode) - the string khbjahpecnkenngkidhioicnfpakihgo under the iframe_raw.js is the Super Full Feeds for Google Reader extension. Based on it's description:
Super Full Feeds for Google Reader™ enables full content feeds for Google Reader™. Provides readable content or iframing of feed entries. Settings are per feed or folder and are transparently built into Google Reader™.
...
- Pre-fetch readable content for unread entries (optional).
It looks like it might be preloading stuff for you, which might be pulling in those advertisement/tracking sites.
Try disabling that extension in Chrome and see if your log looks any different in regular mode.
If it is the DNS caching on your system, try stopping and restarting the DNS client service in windows.
You can do this by running the following commands:
net stop dnscache
net start dnscache
Then confirm the cache is clear with:
ipconfig /displaydns
Plan B:
Close and reload Chrome. Confirm chrome is closed by checking in the task manager. (many extensions and plugins like to keep Chrome open in the background - like Hangouts, for example.)
Plan C:
Ping the site...
ping www.superuser.com
Pinging superuser.com [198.252.206.140] with 32 bytes of data:
Reply from 198.252.206.140: bytes=32 time=39ms TTL=52
Reply from 198.252.206.140: bytes=32 time=40ms TTL=52
Reply from 198.252.206.140: bytes=32 time=41ms TTL=52
Reply from 198.252.206.140: bytes=32 time=42ms TTL=52
Ping statistics for 198.252.206.140:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 39ms, Maximum = 42ms, Average = 40ms
Plan D:
An old Windows adage, but when all else fails, reboot.
Useful site: http://www.downforeveryoneorjustme.com/ - check the sites you are trying to access.
Another useful site: http://downdetector.com/ - Reports of outages on services and websites.
Best Answer
Currently, the only simple solution is to use an extension.
Before Chrome version 33, released 20th February 2014, this solution was possible:
You may have to click on the 'x' on the right of each cached thumbnail to get rid of it.
At the time of writing, September 2013 this worked.