I'm using pinentry-gtk-2 on Tails 2.0 which is based on Debian Jessie with
GNOME3 in classic mode. I found multiple unexpected behaviors:

If I open the applications menu while the pinentry-gtk-2 password prompt is open
and click on an item to open an application, the menu becomes unresponsive and
the application does not open.

If I right click on any window's title bar, the context menu appears but is
unresponsive and can't be closed.

In some windows, right clicking does not open the conext menu (e.g.
gnome-terminal, gedit), in other windows it does.

I got this behavior with all the versions I tested, which are the pinentry-gtk-2
packages from Debian stable/jessie (0.8.3-2), Debian testing/stretch (0.9.7-1)
and Debian unstable (0.9.7-3). The first time I tried the package from testing,
I tested only the applications menu behavior and could not reproduce the bug.
But on subsequent tests the bug reappeared.