A lot of usability work focuses on solving interface problems, making it easier for users to achieve a certain outcome or complete a task. This can involve user observations, iterative design changes, traffic analysis and other tools in pursuit of improvement. It is often not cheap in terms of time and effort, let alone when outside help is brought in.
A solved usability problem is one where both the user and the publisher get precisely what they want from the interaction. The user has an efficient and pleasant experience and the publisher gets the user to complete a desired task. All is well in the world.
A resolved usability problem is one in which a reasonable compromise is reached that is good enough but requires that either the user or publisher (or both in some cases) give up something. For example, the user experience might still have some rough spots but the value of the transaction doesn’t warrant further investment or outside factors impose it.
However, something a lot of people fail to consider is if the interface in question can be completely eliminated instead of ‘fixed’. Instead of solving the problem, can you dissolve the need for this interface completely? Sometimes making a few changes to the larger system of which the interface is a single element can completely eliminate the need for the interface.
This isn’t an option all the time, obviously, but the only way to know is to consider the larger context of the problem at hand. Simply focusing on individual interfaces is inadequate.