Firefox address bar autocomplete results detached from address bar

[Jay]

1. Version/environment information
Mint 17.1 Rebecca 64-bit, Cinnamon edition
Firefox (package version 46.0+linuxmint1+rosa)
Two monitors

2. Observed behavior
The Firefox address bar/awesomebar autocomplete results detach from the address bar, rendering elsewhere on the screen, sometimes outside of the Firefox window entirely, or on a different monitor.

3. Expected behavior
The autocomplete results should be attached to the Firefox window directly beneath the address bar.

4. Reproduction
- Open Firefox.
- Move and resize the Firefox window.
- Click the awesomebar down-arrow to open it, or begin typing in the address bar.
- Note the awesomebar results are not correctly located.

It happens every time, as far as I've noticed. Sometimes it takes slightly longer, but it's reliable. This began happening after the most recent Firefox package update a few days ago.

[darkfur93 (darkfur93-u)]

I have the same problem.
Build identifier: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:46.0) Gecko/20100101 Firefox/46.0
I have 1 monitor @ 1920 x 1080.
I'm using a Radeon HD 6900 Series video card with the fglrx driver.

[Jay (slater-jay)]

Here's an image showing the problem.

[Jay (slater-jay)]

Still present with 46.0.1.

[Jay (slater-jay)]

This also occurs in the non-Mint Firefox 48 beta, although it seems to be harder to trigger.

[Jay (slater-jay)]

I believe this bug was introduced in the Cinnamon update I installed on 4.16.16, going from 2.4.6 to 2.4.8.

[nibbler (robin-telenet)]

Still present in 47.0
Also present in "classic" Linux Mint.

[aqsalose (aqsalose)]

Also affects me. Two screens, autocomplete results consistently open on the wrong screen. Firefox 48.0 [Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:48.0) Gecko/20100101 Firefox/48.0]. Mint 17.3 / Cinnamon 2.8.8. (Linux 3.13.0-24-generic x86-64).