If you do much work in Keynote, you’re probably aware of most of the useful shortcut keys you can use during a presentation—things like pressing the Space Bar to move forward to the next build on your slide, H to hide the presentation and switch to the last application used, and Home or End to jump to the first or last slide. There are actually a ton of these shortcuts, and you can see the full list by pressing the “/” key (that’s the slash key) while in presentation mode.
Two of the more useful shortcuts are the “[” and “]” keys (open and close brackets), which jump to the previous or next slide, respectively. Most of the time, that is, they’ll jump from one slide to the next. But on seemingly randomly selected slides, it seems they sometimes won’t work as expected. It turns out that if your slide has timed builds—where one action happens automatically after some time interval—these previous and next slide shortcuts may not work. I’ve found that they seem to work OK on some timed build slides, but not others.
The solution turns out to be easy, but (as best as I can tell) completely undocumented: just hold down the Option key prior to pressing either the “[” or “]” keys, and Keynote should skip the timed builds and jump directly to the previous or next slide. Your mileage may vary, but this trick has worked for me in the past.