Why are my images N/A despite being downloaded correctly?

Web Performance Discuss Test Results
1

When I do a test for the more recent websites I’ve been launching they will always get N/A for the ‘Compress Images’ item, and the “Progressive JPGs” item will not even appear at all, even when the site is entirely built using progressive jpgs.

Would appreciate any info or insight into why that might be happening.

Samples tests where this has happened recently:

http://www.webpagetest.org/result/140819_WH_J3D/ (website made entirely with progressive jpegs)

http://www.webpagetest.org/result/140819_F8_J5M/

http://www.webpagetest.org/result/140819_TA_J6X/

(These are all on cheap shared hosting so the first-time byte is expected to be bad).

You can see in the thumbnails of the tests that the images are being downloaded and read.

Now, if I remove the caching block I use from the htaccess, now the items will appear but obviously I get a bunch of F’s now for not caching properly:

http://www.webpagetest.org/result/140819_RQ_J99/

This is the caching block I’m sing in my htaccess:

Enable keep-alive

Header set Connection keep-alive

Compress text, html, javascript, css, xml:

AddOutputFilterByType DEFLATE text/plain
AddOutputFilterByType DEFLATE text/html
AddOutputFilterByType DEFLATE text/xml
AddOutputFilterByType DEFLATE text/css
AddOutputFilterByType DEFLATE application/xml
AddOutputFilterByType DEFLATE application/xhtml+xml
AddOutputFilterByType DEFLATE application/rss+xml
AddOutputFilterByType DEFLATE application/javascript
AddOutputFilterByType DEFLATE application/x-javascript
AddOutputFilterByType DEFLATE image/jpg
AddOutputFilterByType DEFLATE image/jpeg
AddOutputFilterByType DEFLATE image/gif
AddOutputFilterByType DEFLATE image/png

Or, compress certain file types by extension:

SetOutputFilter DEFLATE

BROWSER CACHING

ExpiresActive On
ExpiresByType image/jpg “access 1 year”
ExpiresByType image/jpeg “access 1 year”
ExpiresByType image/gif “access 1 year”
ExpiresByType image/png “access 1 year”
ExpiresByType text/css “access 1 month”
ExpiresByType application/pdf “access 1 month”
ExpiresByType text/x-javascript “access 1 month”
ExpiresByType application/x-shockwave-flash “access 1 month”
ExpiresByType image/x-icon “access 1 year”
ExpiresDefault “access 1 week”

BROWSER CACHING

Thanks for any help.