Page note found (different)

I’m trying to create a bilingual Advanced Search page.
The french page works perfectly, but for the english one, it says Page not found. The page does exist in my dashbord though and I have the right URL.

I read a past thread about this but it has nothing to do with RSS. I tried deleting every Advanced Search page I had in my list to make sure I had only one with the same URL but it still wouldn’t work.

I tried with using the permalink in my widget instead of the full URL but it didn’t work.

Please help!!

Site is http://www.reptic.qc.ca