Hi,
Would it be possible to have a little more details ?
When you click on a link which result to a download, your browser generally keep display the previous page, but it the link is open in a new window/tab, you will have a blank page because you do not have a previous page to display.
Regarding to the possibilities of HTTP and your request, I'm not sure that it will be possible like that.
Regards,
Jerome - Obsidev.com
HikaMarket & HikaSerial developer / HikaShop core dev team.
Also helping the HikaShop support team when having some time or couldn't sleep.
By the way, do not send me private message, use the "contact us" form instead.