Hello,
Such behavior is generally caused by plugins like shipping plugins.
If you do have UPS/Fedex/etc plugin and it require to perform web services calls to get a shipping estimation ; it could delay the page processing and give you such kind of issue.
So it would be interesting to have more details about your HikaShop configuration.
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.