What you're seeing frequently happens
when there is some kind of disruption
while the information is being fetched,
before it is displayed. As suggested,
this can happen when getting low on
memory and your system has to pause
while it shuffles things around and gets
rid of old stuff to make room for, and
before loading, more new stuff... or it
can also be caused by network problems
(interruption in your connection). Very
very unlikely to be a problem with Yahoo,
nor a problem with Chrome/Chromium.