InDesign CS6 text frames acting wonky

Question

I started a brand new document. Some text has been copy/pasted from CS4 documents or Word but all of it is acting weird. If the text frame is less than 7.4375 in wide, then it breaks and reflows at odd points and I can't seem to get the frame to end where I want it to.
I don't know where to look to fix whatever setting is doing this.
Above: Text frame at margin width less than size noted above. but when the frame is extended to the margin height, it breaks the text and doesn't keep it where I want.
Below: Text frame at 7.4375 in wide. It will break at different places and show all that's supposed to be in the frame

Answer 1

First, show non-printing characters so you can look for non-breaking spaces. Next check for a long string of text to which No Break has been applied (if you make the frame narrow and the text goes into overset, it's easiest to find these problems by looking at the first bit of text past the overset indicator in the Story Editor). The next possibility, which would be reinforced by large changes in where the text goes into overset whenyou adjust the frame heith only slightly, is that there are keep options applied that prevent ID from fitting all of the required text into the remaining space in the frame.