Position of the helper is wrong

Hello,

I have a problem with the offset of the helper

If the parent of the helper(lasso) has an offset from the page the offset of the helper(lasso) is positioned as if it's parent didn't have an offset.

In my case the page is very long, so you can't see the helper anymore.

There is a similar ticket #4377, but the provided patch there did not solve the problem.

I created a testcase. http://jsbin.com/ofixa

You need to scroll down the div to see the drag items (to demonstrate the issue).

Thanks

Axel