There's actually several versions that don't have anything to show in the analysis window. In order for something to show up there, the version you are using must be "tagged" in some way. For instance, the NASB (NAU) has strong's numbers tagged to it. You can turn the actual numbers on and off by double-clicking the word "Strong" in the status bar. So when you use the NAU, you can see word info in the analysis window that corresponds to Strong's numbers. Of course, same for the KJV.
The Greek versions will always show greek word info for obvious reasons. Other versions that have notes with them will have their notes displayed there. A good example is the NET bible. It has lots of study notes, so when you mouseover a verse, those study notes appear. The ESV has cross references.
Since the NIV is not tagged with Strong's numbers and does not have any study notes, there just isn't anything to show. If you'd like more information when you are browsing, use toggle the browse mode when you are in the browse window by typing a 'b'. Then you'll see a variety of versions (you can customize which versions are displayed). If you choose the NAU, NET, and a greek version like BGT, then when you are looking at a verse in the NIV, you only have to mouseover the same verse in the other versions to see additional information.
"Contend earnestly for the faith that was once for all delivered to the saints." Jude 3 (ESV)