Joomla Virtuemart Store - Google PageSpeed Insights telling me GZIP not working.

After running a page speed test on Google PageSpeed test it was coming up that many pages weren't being Gzipped.  Even though this GZIP test http://www.whatsmyip.org/http-compression-test/ was telling me GZIP was activated. 

I checked that the feature was active in Joomla .  This is in

> admin
> click on 'site'
> drop down to 'global configuration'
> click on 'server' tab
> and make sure the 'GZIP Page Compression' radio button is ticked.

What I did to solve the issue was to untick this feature and do the gzip by .htaccess instead.  

Here's a guide on to do this 'use gzip in .htaccess'

in short you need to use this code in .htaccess

SetOutputFilter DEFLATE