This new format for asking questions?

That's one of the many glitches with new format. Sometimes you can reload the page and it may work the next time, or you may have to reload it many times in order for it to work. Sometimes you can't get the next 20 items to ever load for a while, trying again in a few hours or days sometimes fixes that.

Also, for now, you can go to one of the other English sites that use the old format (personally, I've been hiding out on Yahoo! Answers Canada). The English sites all share the same pool of questions, so you won't miss out on any of that.

Do you go to those categories where questions you like answering are most likely to appear?

If you like the "All questions" Home page, then just keep reloading. You'll get a new batch of questions every couple of minutes at the longest.

Sorry, I don't know the ins and outs of the new format, as I hated it so much I switched to using the YA Canada site. You could consider also changing to the YA from another English-language country (make sure you are viewing ALL English language questions, and NOT the questions from a particular country only).

You may need to clear your cache, temp, and cookie files. That sometimes works. Other times, just going to a totally different page on YA and then coming back will also do it. If on a phone, try switching to desktop mode. Lastly, make sure your Java and Flash are current with updates. This applies mostly if you are using XP and IE8, but should be done with all browsers.