I got a reply from Hauppauge tech support:
"The AVC-HD standard is a widely supported format but there are some
blue ray players that do not support it. Please consult with your blue ray
player instruction manual to see if it is supported."
If that is the case, wouldn't it be more honest if you added a list on
your web site that shows which Blu-Ray models will play the discs your
system creates, and which will not? On your FAQ you do not indicate
that there is any compatibility problem with some Blu-Ray models.