So I came across this annoying cursor behavior while trying my brand new Mathematica 10:
Suppose you have a Ctrl+= input in cell 1, then you work your way to cell say 15 (the horizontal line now lies under cell 15 and cell 1 is out of view), if you want to edit that Ctrl+= input you scroll to cell 1 and click on the left of that Ctrl+= input, what happens to me is that the notebook scrolls down to where the horizontal line is, after cell 15 and cell 1 is out view again. It's annoying because you cannot see what you type on cell 1.
Can you reproduce this or is it just happening to me? I am using Mathematica 10 on OS X Mavericks.
I have attached a notebook that hopefully illustrates the problem.
I have a similar issue in Mathematica 10.0 using Windows 7 Professional. The cursor disappears whenever entering a equation on a DisplayFormula cell. Focus cannot be set to a palette block by clicking a block. Pallet blocks don't highlight and the cursor disappears. Entering a display formula is pretty much trial and error without visual feedback.