I don't know about #1.. I would like to know too!

But for #2.. perhaps it's the smell? When Bassett peed on the floor a while back (grr!) after it was all cleaned up but before I could put the odour remover (this was only a matter of minutes while I ran to the kitchen..) Tilly and Nutmeg were there really fast trying to cover the smell. If her urine is really strong (has her food changed or something??) maybe she can still smell it outside the box and is trying to cover it up?

I hope someone can give you some better answers!