Comment 29 for bug 335732

Confirmed on vivid...

Here's the lazy man's fix. It'll replace the dash Skype icon launching command to unset XMODIFIERS before launching skype.

You just have to copy paste in a shell:

DESKTOPFILE=/usr/share/applications/skype.desktop
if [ -e "$DESKTOPFILE" ]; then
    sudo sed -ri 's/^Exec=skype %U$/Exec=env -u XMODIFIERS skype %U/g' "$DESKTOPFILE"
    echo "Found and updated $DESKTOPFILE."
else
    echo "Not Found, NO correction applied."
fi