FF 36: Number of blocked requests on icon changes appearance

[FatOrangutan]

This started happening after upgrading to Firefox 36.0. The number of blocked requests normally looks like this:

But if I go into Customize (Firefox Menu -> Customize) and come back (don't necessarily have to change anything while in Customize mode), the icon now looks like this:

I am using the standard Firefox theme.

[TheSweetLily]

Can confirm it on my end, too.

Mozilla/5.0 (Windows NT 6.1; WOW64; rv:39.0) Gecko/20100101 Firefox/39.0 ID:20150225030226 CSet: 07c04d7a483a

µBlock version: 0.8.8.5-dev.2

[gorhill]

Duplicate of #579.