I too, have done my computer "housekeeping".
I go through regularly and empty out these things. Is it possible that a good cookie was deleted, when perhaps it shouldn't have been?

When I was into iom.com the day before the new website was launched, the text was unusually spread out right across the page, the first letter hard up against the l/hand margin and the last letter on the line hard up against the r/hand margin - it looked wierd but at least was readable. Once the new website was launched, everything was center/right making it necessary to continually move the page to the left in order to read each line.
Logic tells me that it must be something under their control, I have never known this before on any other site.