Sometimes when I've got channels selected in the F-Curve editor and hit "V" to make them visible, it doesn't actually work. (Yes, my mouse is over that section!)

This usually occurs when I have many (or all) channels currently visible, and only want a portion of them to be visible.

Although I think this happens in several different situations, here's an easy way to reproduce:

select all channels. Hit V. With all channels still selected, border select with ALT to deselect certain channels. Now when you hit V, nothing happens.

Expected behavior would be to have all the other channels disappear.

To workaround you've gotta deselect, then select.