wrong rendering of Planet's shadow

with version 0.12.0 the new rendering allows shadow casting of planets on satellites and vice-versa.

Saturn casts a wrong shadow onto the rings: it is smaller than the planet diameter.

this error is visible for example going to the "Solar System Observer" object and zooming to Saturn.
if you set the date to 2016 january 24th you can see Saturn from one Pole and the shadow appears smaller then the planet's diameter.

this is the firs time I post a bug here, so I don't know if I succeed in posting also a snapshot, but it's even unnecessary: the bug is always present...

related to the incorrect rendering of the shadow, are also the wrong timings of ingress ad egress of Jupiter's satellites into the planet's shadow, even setting correctly the "Simulate light speed" option in the "Sky and Viewing Option Window" [F4]
I found discrepancies of even 1 hour for Callisto start time of eclipse, reduced to about 15 minutes for the end time of eclipse, for 2019 november 9th, during one of the rare events in with Jupiter appears moonless, with Europa and Callisto eclipsed and Ganymede and Io in transit.

thanks!

here is my log.txt

2013-02-22T17:47:42
Windows 7
Compiled using MinGW GCC 4.6.1
Qt runtime version: 4.8.2
Qt compilation version: 4.8.2
Addressing mode: 64-bit
Total memory: 4078 MB (unreliable)
Total virtual memory: 8388607 MB (unreliable)
Physical memory in use: 41%
Processor speed: 2793 MHz
Processor name: Intel(R) Core(TM) i5-2300 CPU @ 2.80GHz
Processor speed: 2793 MHz
Processor name: Intel(R) Core(TM) i5-2300 CPU @ 2.80GHz
Processor speed: 2793 MHz
Processor name: Intel(R) Core(TM) i5-2300 CPU @ 2.80GHz
Processor speed: 2793 MHz
Processor name: Intel(R) Core(TM) i5-2300 CPU @ 2.80GHz
C:\Program Files\Stellarium\stellarium.exe
 -------------------------------------------------------
[ This is Stellarium 0.12.0 - http://www.stellarium.org ]
[ Copyright (C) 2000-2013 Fabien Chereau et al ]
 -------------------------------------------------------
Writing log file to: "C:/Users/packard-627009/AppData/Roaming/Stellarium/log.txt"
File search paths:
  0 . "C:\Users\packard-627009\AppData\Roaming\Stellarium"
  1 . "."
Config file is: "C:\Users\packard-627009\AppData\Roaming\Stellarium/config.ini"
Going to initialize the OpenGL 2 renderer
OpenGL supported version: "3.3.0"
Qt GL paint engine is: "OpenGL2"
GL vendor is "NVIDIA Corporation"
GL renderer is "GeForce 405/PCIe/SSE2"
Log of the compilation of builtin shader " plainShader " : "Built successfully"
Log of the compilation of builtin shader " colorShader " : "Built successfully"
Log of the compilation of builtin shader " textureShader " : "Built successfully"
Log of the compilation of builtin shader " colorTextureShader " : "Built successfully"
Cache directory is: "C:\Users\packard-627009\AppData\Local\stellarium\stellarium\cache"
Sky language is "en"
Application language is "en"
Loading Solar System data ...
Loaded 74 / 74 planet orbits from "C:\Users\packard-627009\AppData\Roaming\Stellarium/data/ssystem.ini"
Loading star data ...
"Loading "./stars/default/stars_0_0v0_1.cat": 0_0v0_1; 5013"
"Loading "./stars/default/stars_1_0v0_1.cat": 1_0v0_1; 21999"
"Loading "./stars/default/stars_2_0v0_1.cat": 2_0v0_1; 151416"
"Loading "./stars/default/stars_3_1v0_0.cat": 3_1v0_0; 434064"
"Loading "C:\Users\packard-627009\AppData\Roaming\Stellarium/stars/default/stars_4_1v0_0.cat": 4_1v0_0; 1725497"
"Loading "C:\Users\packard-627009\AppData\Roaming\Stellarium/stars/default/stars_5_2v0_0.cat": 5_2v0_0; 7669011"
"Loading "C:\Users\packard-627009\AppData\Roaming\Stellarium/stars/default/stars_6_2v0_0.cat": 6_2v0_0; 26615233"
"Loading "C:\Users\packard-627009\AppData\Roaming\Stellarium/stars/default/stars_7_2v0_0.cat": 7_2v0_0; 57826266"
"Loading "C:\Users\packard-627009\AppData\Roaming\Stellarium/stars/default/stars_8_2v0_0.cat": 8_2v0_0; 116923084"
Finished loading star catalogue data, max_geodesic_level: 8
navigation/preset_sky_time is a double - treating as jday: 2.45151e+06
Loaded 10051 NGC records
Loading NGC name data ...
Loaded 288 / 288 NGC name records successfully
Loading star names from "./skycultures/western/star_names.fab"
Loaded 230 / 230 common star names
Loading star names from "./stars/default/name.fab"
Loaded 3215 / 4359 scientific star names
Loaded 88 / 88 constellation records successfully for culture "western"
Loaded 85 / 85 constellation art records successfully for culture "western"
Loaded 89 / 89 constellation names
Loading constellation boundary data ...
Loaded 782 constellation boundary segments
Not using any viewport effect
Creating GUI ...
Loading shortcuts...
Loaded plugin "AngleMeasure" .
AngleMeasure plugin - press control-A to toggle angle measure mode
Loaded plugin "CompassMarks" .
CompassMarks plugin - press control-C to toggle compass marks
Loaded plugin "SolarSystemEditor" .
Using the ssystem.ini file that already exists in the user directory...
Loaded plugin "TimeZoneConfiguration" .
Simple planet shader build log: "Built successfully"
Shadow planet shader build log: "Built successfully"
Using vertex shader for atmosphere rendering.
Atmosphere shader build log: "Built successfully"
Build log after adding a Mat4d transform shader: "Built successfully"
Build log after adding a stereographic projection shader: "Built successfully"