Problems with slideDown on Firefox and IE

Problems with slideDown on Firefox and IE

Hi all,

To begin, i want to say that i'm french and consequently, i'm sorry for my bad english .

Like the title tells, i have a problem with slideDown on IE and Firefox. On Firefox, that makes gaps between my Menu and my footer and i don't know why... On IE, the slideDown is too fast and i don't know how i can fix this trouble.

Can someone help me please? I've uploaded my files on my FTP :



http://coenonympha.free.fr/Site.zip

Thanks for replies