I use firefox, and I was getting frustrated that I couldn't make my +10 ADRs, without getting error messages, so I had to call them to make them all (not easy with my 2.5 yo around)... a few days later I needed to cancel & rebook an ADR that was still in my +10, so I decided to try it using Internet Explorer (which I NEVER use) and it worked great - it really would have saved me from the headache caused by trying to keep my toddler entertained & happy while I talked on the phone if I had known from the beginning
I woke up at 5 am (central time) and it was a long wait until I could call at 6, - I had wasted almost the whole hour trying and trying to get them to go through...