Comment From: rusackas
I thought this is the desired effect... when you hover, you get more detail (the exact value) rather than the formatted one. This applies to percentages, or other formats (e.g. 12,002 displayed as 12K).
Should be simple enough to have the "title" attribute of the HTML cell show the formatted value, but I always figured the title (hover) attribute with the actual value was pretty handy.
CC @mistercrunch for any historical context here, or @kasiazjc for any design thoughts.