I had the same issue with my text boxes. For the life of me I hadn't figured out what was going on. I stumbled upon this thread and started clicking around. All of my values on my spacing palette were set to zero. However, once I started to manually plug in zeros again, the paragraph indentation leading value suddenly switched from 0 to .25 even though it was registering zero before hand. I am not sure why this occurred, but I was able to see where the issue was and correct the text boxes from doing it further.
