Does not work on certain websites

[urbainvaes]

Many thanks for this great program!

On youtube and some other websites like soundcloud (I think), the program behaves unexpectedly. E.g. sourcing the following:

setxkbmap us
xmodmap -e "keysym space = Super_L"
xmodmap -e "add mod4 = Super_L"
xmodmap -e "keycode any = space"
xcape -e 'Super_L=space'

On pressing the space key, a space keycode is sent directly to youtube.

I use i3 on Archlinux. Information from debug mode: when it works, here is what is printed:

Key pressed!
Intercepted key event 3, key code 65
Key released!
Generating space!
Ignoring generated event.
Ignoring generated event.

When it doesn't work:

Intercepted key event 2, key code 65
Key pressed!

so a space appears to be generated although this does not appear in the debug information.