Javascript - D.o.b drop down issue?

Hello there,

I’m having a few issues with java-script and my date of birth drop down menu:

When I remove all the java-scripts, the drop works fine. But as you can guess I need to keep all the scripts, especially the jScrollPane. Which I can imagine is the root of the problem.

Would anyone know how I could solve this issue?

I am no javascript guru, but it could be something to do with the height of the dropdown menu.