Another thing to check...

Those HR20-700 (clean) codes came from me and I discovered that one version of that clean library file had some flaws (copy-paste issue, file corruptions or issues with that particular makehex or irp version I was using to create the codes???). I had macro issues as you mentioned and the channel up/down was initiating a crazy endless channel scroll. On at least one job, I reverted to a learned library file (be careful of this as well because those codes can ofter learn in with flaws) to solve the issue. I will be implementing several different DTV boxes on a job next week. I can test those clean codes and report back.