wpp_search

Hello,
sorry for my bad english. I have a problem with the search module.

when I click on the search button, the given url is:
http://absis-immobilier.fr/?p=property&wpp_search%5Bpagination%5D=off&wpp_search%5Bper_page%5D=5&wpp_search%5Bstrict_search%5D=false&wpp_search%5Bproperty_type%5D=maison&wpp_search%5Bprice%5D%5Bmin%5D=&wpp_search%5Bprice%5D%5Bmax%5D=&wpp_search%5Bdeposit%5D=-1

but if I manually change the url like this it works :
http://absis-immobilier.fr/?wpp_search%5Bpagination%5D=off&wpp_search%5Bper_page%5D=5&wpp_search%5Bstrict_search%5D=false&wpp_search%5Bproperty_type%5D=maison&wpp_search%5Bprice%5D%5Bmin%5D=&wpp_search%5Bprice%5D%5Bmax%5D=&wpp_search%5Bdeposit%5D=-1

p=property&

this poses a problem how to fix it?

thank you

The page I need help with: [log in to see the link]