When you move virtuemart from one URL to another, you have to update the URL settings in your virtuemart configuration. This also applies to moving from or to a subdomain or folder.

To update this file after moving your shop, FTP to your host.
Download    virtuemart.cfg.php
Path to File Here
administrator/components/com_virtuemart/virtuemart.cfg.php

Change your shop URL, and your Secure URL to your new shop address.Both must have either the www. or non-www. They must match UNLESS one is https but it styill must contain the www or non-www like the other one.

If you moved from one host to another, and your thumbnails are not showing
Most of the time you need to re-create the thumbnails. This is done by

Go into your virtuemart administrator. Then to configuration, and then the "site tab".

Disable "Enable Dynamic Thumbnail Resizing?" Save Your Changes
Then Re-enable "Enable Dynamic Thumbnail Resizing?" Again, and Save.


Also Make Sure The Image Directory is 755

This can cause missing thumbnails