Sometimes things slip through the cracks. Unfortunately, what's missed can cause you to lose a good portion of your profit and you just have to suck it up and take it. I'm happy to say that I figured out how to program my Etsy shipping settings to calculate actual package weight rather than charging a flat $4 fee. It wasn't really a huge deal until I had two back-to-back packages to Australia and ended up eating a $13.20 postage fee TWICE! Yikes! Rather than say anything (because hey - that $4 fee WAS my posted worldwide shipping policy), I just went ahead and ate it. But at least it's fixed so it won't happen again!