Prism's frequency distribution analysis takes a stack of values and creates a frequency distribution table. You can choose the bin width, or Prism can choose it for you.

If you create a series of frequency distributions from different data tables, you'll want the range to be the same for all. However,  Prism stops making bins when it gets to the largest values. If different data sets have different ranges of data, the distributions won't be consistent and graphs of those distributions (histograms) won't align.

With Prism 5, this is easy to fix. On the Frequency Distribution dialog, choose a large value for the last bin -- large enough to include all the values in all your data sets. Choose the same value for all the analyses that you want to plot together.

With Prism 4, it is not possible to set the center of the last bin. Prism stops when it runs out of values. The only way to get consistent graphs would be to copy the results and paste onto an empty data table. Then you can add additional bins (X values), each with zero for the Y values.

Windows

Prism Windows fills one window (with other windows inside of that one, if you open several projects). You can move that Windows around, and move it to a different display. 

If the Prism window is  on the primary display, then Prism remembers its size and location. Next time you start Prism, it will appear in exactly the same location. 

If you move Prism to a different display, it gets confused. Next time you start Prism, it will start on the primary display. But you can trick Prism to get it to start on a different display. The first thing to do is click the Restore button near the upper right corner, so the Prism window does not entirely fill the display. Now grab its corner and stretch it, so a tiny part (just one pixel is enough) is on the primary display, while most of the window remains on the secondary display. Now when you quit Prism, it will remember its location and start up next time in exactly the same location with the same size. The trick is that part of the Prism window needs to be on the primary display -- but it can be a very tiny, almost invisible, part. 

Mac

Each Prism document is in its own Window, which you can move anywhere. You can have one project on one display and another project on another. 

When Prism starts up, the first project is always placed on the primary display. You cannot tell Prism to always start on a different display.

As part of nonlinear regression, Prism 5 can compute the replicates test. It asks if the deviation of the points from the curve is 'too far' compared to the scatter among the replicates. Prism does the calculations correctly, but we just learned that the explanation in the Prism help is incorrect. Details here.