How to reproduce:

Open a group with many messages to translate in TUX in translation mode.
Open the first row - the IME selector is displayed below the translation textarea.
Scroll down and open a row further down - the IME selector is displayed *above* the translation textarea.

This is already fixed in GitHub and committed in Gerrit:
https://gerrit.wikimedia.org/r/#/c/64474/

Version: master
Severity: normal