I have tracked down the source of the problem, sort of. I notice that when I go into the products to edit them, the flat rate shipping is set to 0.00. When I delete it and click the CHECKMARK right beside it to save, the flat rate shipping goes blank and the flat rate shipping amount that I put in the flat rate shipping extension works, AS LONG AS I don't click SAVE at the very bottom of the page. But, if I click on SAVE at the bottom of the page, the blank box changes to 0.00. So, anytime I would have to edit that product, which would make it necessary to click on SAVE, it messes up shipping by automatically changing it to 0.00. Can someone look into this? Is it a bug? Attaching pics..
Thanks!