You guys are goofy. HAH GOOFY, get it? Disney site?
*ahem*
OK leaking water, but non upstairs.
It could be several things. A broken pipe somewhere perhaps? Could be a slowwwww leak.
We've had our living room ceiling leak because strong winds were blowing water up into and between somewhere-or-other...not sure exactly....but no wetness upstairs but wet ceiling downstairs. Maybe you've got some wind driven rain entering your house that way?
Hm....I'll think of others I'm sure. LOL