No Pinto pattern in any breed, or Appaloosa pattern, can be passed on if the parents are truly solid.
The problem arises out of defining "Solid" as the Pinto people call a blaze faced four white socked horse "Solid" thus, as we well know, if you breed two of those together, you can get some wild results!!
Frame cannot be carried, any more than any other pattern, BUT again, define solid as blue eyes alone can and do indicate the presence of Frame or Splash.
In Appies it needs only to have white sclera, striped hooves and mottling- sometimes only one of these characteristics is enough.
Sometimes these things pass completely unnoticed and a horse gets registered as "Solid" and thus the confusion began.
When you have a registry that relies on a pattern, and sets regulations that define that pattern, you will always get this problem.
I know, of course, there must be rules, that only makes sense, but it also makes sense to enter the 21st Century and get the definitions straight.
At least the majority of Mini people are trying to understand- now, if we could just get the people who actually are responsible for the registrations to take some interest...