From #2319 and the forum:
us.yhs4.search.yahoo.com/yhs/search;_ylt=A0oG7qCW9ZhNdFQAuTQPxQt.?q=xxxxxxx
us.nc.yhs.search.yahoo.com/if?p=keyword1+keyword2+keyword3&partnerid=yhs-if-timewarner&fr=yhs-if-timewarner&ei=UTF-8&YST_b=7&vm=p
search.babylon.com/web/xxxxxx
(In [4696]) fixes #2304
This is the quick fix. Wildcard matching just isn't workable in the current algorithm. The "right" way may be to extract the "provider" (similar to the Provider plugin, or using the Public Suffix List).