tinting/shading doesn't work with xfree86 4.3/fvwm2

[Médéric Boquien]

Hi list !

I'm having some problems getting the tinting and the shading work with 
xfree86. When i want to get a transparent terminal using the .Xdefaults file 
with the parameters : 
URxvt*inheritPixmap:true
URxvt*tintColor:red
URxvt*shading:50
URxvt*fading:75
URxvt*scrollColor:AntiqueWhite
URxvt*scrollstyle:plain
URxvt*scrollBar:true
URxvt*saveLines:1000
URxvt*cursorBlink:true
URxvt*deletekey:^H
URxvt*foreground:antiquewhite
URxvt*cursorColor:blue3

The tinting and the shading doesn't work at all, the terminal is just 
tranparent, as can be seen on this screenshot 
http://mboquien.free.fr/rxvt.png . This happens on a "scientific 
linux" (https://www.scientificlinux.org/ ; xfree86 4.3), with rxvt-unicode 
5.0 using those configure parameters : ./configure --enable-combining 
--enable-xft --enable-font-styles --enable-utmp --enable-wtmp 
--enable-lastlog --enable-xpm-background --enable-transparency 
--enable-tinting --enable-fading --enable-menubar --enable-half-shadow 
--enable-mousewheel --enable-slipwheeling --enable-cursor-blink 
--prefix=$HOME/local --enable-plain-scroll. As i am not root on this 
computer, it is installed in my ~. Using the same parameters with xorg 6.8.1 
on a gentoo linux, everything works as expected.
What can i do to get the tinting/shading work as expected with xfree 4.3? 
Thank you very much for any help and congratulation to the programmers for 
this very neat terminal. :)

Regards,

Médéric

PS: here is a part of my xdpyinfo output in case it would be useful
xdpyinfo 
name of display:    :0.0
version number:    11.0
vendor string:    The XFree86 Project, Inc
vendor release number:    40300000
XFree86 version: 4.3.0
maximum request size:  4194300 bytes
motion buffer size:  256
bitmap unit, bit order, padding:    32, LSBFirst, 32
image byte order:    LSBFirst
number of supported pixmap formats:    7
supported pixmap formats:
    depth 1, bits_per_pixel 1, scanline_pad 32
    depth 4, bits_per_pixel 8, scanline_pad 32
    depth 8, bits_per_pixel 8, scanline_pad 32
    depth 15, bits_per_pixel 16, scanline_pad 32
    depth 16, bits_per_pixel 16, scanline_pad 32
    depth 24, bits_per_pixel 32, scanline_pad 32
    depth 32, bits_per_pixel 32, scanline_pad 32
keycode range:    minimum 8, maximum 255
focus:  window 0x2000026, revert to Parent
number of extensions:    29
    BIG-REQUESTS
    DOUBLE-BUFFER
    DPMS
    Extended-Visual-Information
    FontCache
    GLX
    LBX
    MIT-SCREEN-SAVER
    MIT-SHM
    MIT-SUNDRY-NONSTANDARD
    RANDR
    RECORD
    RENDER
    SECURITY
    SGI-GLX
    SHAPE
    SYNC
    TOG-CUP
    X-Resource
    XC-APPGROUP
    XC-MISC
    XFree86-Bigfont
    XFree86-DGA
    XFree86-Misc
    XFree86-VidModeExtension
    XInputExtension
    XKEYBOARD
    XTEST
    XVideo