OSX upload external changes not working

Hi I'm using 'LESS' (http://lesscss.org/) to generate a bunch of css files into a folder.  The folder is amongst my project and so I was hoping to have it auto uploaded to my dev server (set in deployment with 'upload external changes' ticked).

When a css build is run it's not uploading, even worse I can open a generated css file in Webstorm and it not show the new code!  I'm having to sychronize the file every time.

Is there a way to turn off cache or have it auto synchronise.  having a different version of a file that's not on the underlying filesystem makes me a bit nervous in all honesty.