Ok, after a bit of snooping around I’ve found out a few things.
When you install the quickview plugin from the recommended plugins list, it downloads the latest version from your website:
http://swiftideas.com/extras/plugins/jck_woo_quickview.zip
This is the one which shows up twice in the plugins list after it’s installed and fails to work.
I found a different copy of the file which was included in the theme files:
\Atelier_v1.01\Premium Plugins\codecanyon-4378284-woocommerce-quickview-2\jck_woo_quickview.zip
Installed that one manually and it works fine.
But the files are not the same. The one included with the theme files is 107kb with modified date of 8/04/2015, and the one which is downloaded from your website is 149kb with modified date of 23/04/2015.
Also, if you look inside the zip files, the 107kb file (the working one) has only one file in the root zip folder:
jck_woo_quickview.php
Whereas, the 149kb file has two files in the root zip folder:
jck_woo_quickview (Ed Cousins's conflicted copy 2015-04-06).php
jck_woo_quickview.php
which might explain why it shows up twice in the plugins list after installation.
Any ideas why that one is not working?