[UI] context menu position problem

Hello,

I have a strange problem with PhpStorm 8.0.1 running on Ubuntu 14.04.

Any window / context menu that shows up is showing at the wrong position or with the wrong size.

I attach 3 screenshots:

- code completion menu showing in the upper-right corner instead of showing at caret position
- settings window opening with the wrong size
- project scopes list showing on the right of my screen

Any idea what could cause this ? I could not find any setting to fix the problem.

Thank you,