Could you kindly provide a screenshot?
Your comments don't make it clear if you are having problems with the expense register page or the medication editing page. I've tried both and not had difficulties.
This could be something specific to your PHR, or something is specific to a particular page.
The other think you could do is try editing one of the sample PHRs. Here is a picture of my editing the Jose Gonzalez sample PHR, and editing one of its medications. Notice how the changes to "reason discontinued" cause the page in the "open pages' section to become green, and the save and revert and cancel and OK buttons are enabled?