Problem with Dropdown lists in more-info windows - they appear in the upper right corner - non visible

[krasatos]

When i try to access the dropdown lists from this window:

Let's say i click on the operation dropdown - The list appears in the upper right corner of the window

A scrollbar appears down below and the rest of the items are to the far left:
Here is a screenshot of the bar in the middle where you can barely see both ends:

This does not happen with other themes.
Any idea on how i could start to troubleshoot it?