An alert (and upset) frequent flyer recently posted a cautionary tale on FlyerTalk. The distressed member had been shopping for camping equipment by following the Northwest WorldPerks Mall link to REI.com. While browsing, the member opened two new browser windows, to check for better deals and coupon opportunities.

Once the decisions were made, the items were purchased through the original window.

Eight weeks later, no miles.

Upon calling both REI and Northwest, the confused shopper was told that REI gave the referral credit — what should have been miles — to the “last site” visited prior to placing the order, which, due to the extra windows that had been opened, was not Northwest.

Thus far, the customer has received no response to what are perfectly valid questions.

We’re not singling out Northwest or REI — this sort of problem has been known to happen with other programs and other stores. We simply want to put the word out — be careful when you’re shopping online.

If at all possible, do your research up front and know what you want before you surf. Many retail sites will allow you to build a “wish list,” to which you can post the items you want without actually buying them. This way, you can make your selections, close and reopen your browser, enter the site through the airline’s portal, and your list of merchandise will be saved and ready to buy, all the while giving you proper mileage credit.

If you must have multiple windows open at once, do your research in an entirely different browser than the one through which you wish to purchase.