terminal is not transparent

[Soos Gergely]

I'm using cairo-dock 3.4.0 on top of kde with window manager replaced to compiz-reloaded and emerald. Transparency works very well on my system and other parts of cairo-dock have transparency (the terminal's frame, dock backgrounds etc) except the inside of the terminal even though I've set the background color to half-transparent. Here is the matching line from terminal.conf (I think):

#C+ Background colour:
background color=0;0;0;0.47252747252747251;

This happens with both the cairo and the opengl interface and it was the same with compiz 0.9 before I found compiz-reloaded.
Changing the background to a different color works, only the transparency is not applied.