I'm having trouble, more than I should be, getting Mathematica to have the same preferences having upgraded to version 6.
Namely, I used to be able to magnify an entire notebook by selecting the percentage at the bottom of the window, between the displayed page number and the horizontal scroll bar. Now, selecting it does not seem to work. What preference is overriding this?
Also, especially when opening a notebook created in an earlier version of Mathematica (e.g., 5.2), the cell brackets are not displayed. How do I set the preferences to always display cell brackets, for old notebooks and new notebooks? At the moment, I'm having to select each cell and then open Option Inspector and change the options for Selection. And yes, you can select a cell (or group) even though the brackets are invisible, though it is harder to determine which cell(s) one is selecting.
Creating a new notebook shows that the magnification at the bottom of the window is 80%. But changing this value has no effect. Selecting the cells and choosing Format:Magnification does work.
Third, how do I rescan an old notebook for known issues? M6 has made numerous changes and when opening an old nb, it does a good job of alerting to changed or defunct functions, and other warnings. But, for some of my notebooks, that window no longer appears at the top.
Finally, oddly, my Documentation Center window lost the bar above the ruler but below the toolbar, which contains the forward and back arrows, the home button (for the Doc Center), and the address bar that defaults to guide/Mathematica. What's happened to it? Quitting and restarting Mathematica worked. What kind of error occurred?