Over the past week, the forums were buzzing about Yahoo! Search having some issues. Greg Boser has a good explanation of the issue, where he describes;
Normally, when you search for a term on Yahoo you will never get more than two listings from the same site in the results. However, that clustering feature wasn’t working yesterday. If you searched for a word that appeared on dozens of pages from a single site, Yahoo would show all of them before listing any pages from additional domains.
Lack of clustering makes SERPS virtually worthless. And I can’t think of any other glitches that will cause people to think your results suck quicker than lack of clustering.
But the good news is the problem appears to be fixed.
Well, DaveN noticed the issue is still alive over in the UK.