I had a 104 that did this, i turns out my dog tiped it over onto the concrete floor and caused a crack to form. Not to bad mouth Fluval but their canister filters aren't very strong.
I bet its not leaking from the bottom... but its leaking from the seal.... I used to have a fluval...same thing happened, it looked like it was just sittin in a puddle cause it looked dry... but there was a leak around back and it slowly would drip.