jquery-1.5/iOS 6 compatibility problem

jquery-1.5/iOS 6 compatibility problem

Hello,

I'm new to jQuery and I have to troubleshoot a mobile website for my company. The version is 1.5 so it's ancient. 

On the "slide" transition, it only works if the top of the page is visible. If the page has selections that go beyond the header, nothing happens when you select them. However, if you select the item with the header still on the screen, it functions normally.

I've seen a number of solutions that either don't work for me or I'm not implementing them right. I know the problem is in my jqtouch.min.css file because using a different one fixed this problem (but created others). 

If anyone can offer some advice as to where I should look next please let me know. When I use the latest version of jQuery (1.11.1) the slide function doesn't work at all.

Here's the site: bv.edenred.jp/sp/bv. If you choose the bottom two choices (in Japanese 路線から探す and 都道府県から探す), you'll get a list of choices that continue past the bottom of the screen. If you choose one of the choices below the page where the header is visible, the slide function will not transition to the next page.

Any help would be greatly appreciated. Thank you.