jessie lxde superkey+letter - opens mysterious white textbox

[sombunall]

I don't have any other DE install except LXDE. When I press on the desktop first then superkey and a letter (numbers work like they should with obkey hotkey defining utility) it opens a thin white textbox in the upper right of my primary screen. I can release the superkey and type words in there and press enter. It disappears and does nothing.

I don't want this. I want to map superkey+a to open alsamixer. When I do that it does nothing (it seems to have an impact on the box since it doesn't appear anymore).

I have dual monitors if that matters.

[sombunall]

Ok I mostly solved it. I needed to run a terminal like

urxvt -e alsamixer

for the command to work. But I still wonder what that white textbox is for? Undefined superkey+letter combos will still open it.