Something odd seems to be going on with Yahoo UK - in the last couple of days all my sites on page one of the results keep falling way back in Yahoo UK - then return to their usual position a few hours later - they are currently off the radar again at the moment. Anyone else noticed positions changing significantly for their co.uk and org.uk results?
I came across a forum post on Webmasterworld where others reckon there may be a big Yahoo algo change going on at:
Yahoo is Testing New Algo

EDIT: My sites have all gone back to their previous positions again after 90 mins - very odd!