Hi,
I have read some of the similar posts. I have replaced the front door gasket. It did not stop the leak.
Having read somewhere on this form that the float valve was probably dirty i removed it and cleaned and replaced. I ran a cycle. It worked! no leak!
I did at that time purchase a 'dishwasher cleaner' called:Affresh by Whirlpool.
Thinking that yes, there's film on the dishes and shes been complaining of it for months, I'd also next run a cycle of the Affresh and clean the unit.

Oh my! Leaks......all over the floor!

Help!

I found another post here on the forum mentioning that the air vent at the top of the door of the dishwasher might be plugged with gunk. Sure enough this was the case and Voila!
I have not run 2 complete cycles through the unit with no leaks....
Hope this solves the problem. To refresh:
1) I changed the door gasket. (probably did not need it)
2) Cleaned the float in the bottom of the pan
3) Cleaned the air vent at top of door

thanks to the other posts that had this information in different locations.