On this Shopify store with a current Dawn theme installed, cooltools.us, older versions of Safari keep asking customers to log in while they are just browsing the store, and this continues to happen even when the customers are already are logged in. This happens enough to say it's not a rare anomaly and the store gets regular complaints about it. I've tried to replicate it so far without any success. Store owner says that customers send screenshots, although I haven't seen any myself yet. Tried browser stack with older Safari versions and I'm still not seeing it. Only Safari 6.2 on Mountain Lion refuses to open the page, saying that "Safari cannot establish a secure connection to the server." I'm sure it's somehow related...