Why doesn't CloudFront return the cached version of these identical URL's?

I have a server on eb (running a tomcat application), I also have a CloudFront cache setup to cache duplicate requests so that they dont go to the server.

I have two behaviours set up

/artist/search
/Default(*)

and Default(*) is set to:

Allowed Http Methods  :GET,PUT
Forward Headers       :None
Headers               :Customize
Timeout               :84,0000
Forward Cookies       :None
Forward Query Strings :Yes
Smooth Streaming      :No
Restricted View Access:No

so there is no timeout and the only thing it forwards are queries strings

Yet I can see from looking at the localhost_access_log file that my server id receiving duplicate requests:

127.0.0.1 - - [22/Apr/2015:10:58:28 +0000] "GET /artist/cee3e39e-fb10-414d-9f11-b50fa7d6fb7a HTTP/1.1" 200 1351114
127.0.0.1 - - [22/Apr/2015:10:58:29 +0000] "GET /artist/cee3e39e-fb10-414d-9f11-b50fa7d6fb7a HTTP/1.1" 200 1351114
127.0.0.1 - - [22/Apr/2015:10:58:38 +0000] "GET /artist/cee3e39e-fb10-414d-9f11-b50fa7d6fb7a HTTP/1.1" 200 1351114

I can also see from my CloudFront Popular Objects page there are many objects that hit sometimes and miss sometimes including these artist urls, I was expecting only one miss and there all the rest to be hits

Why would this be ?