Unexplained height re sizing in a JQuery autocomplete input field in a ui dialog

Unexplained height re sizing in a JQuery autocomplete input field in a ui
dialog

I am trying to solve a bug and I have no idea what is causing it.
The input field of a JQuery autocomplete's height is set to 149px:

I don't know what is modifying element.style.
The URL of my testing site is:
http://testing.tostaky.biz/k/kamachumu.html, click on one of the
magnifiers to open the JQuery box.
What is the cause of this height re-size?