second camera issue with android deploiement

Hi,

I have the following issue :
I've got a maincamera showing one first person view and a second camera showing a mini map on top of the player : everything is ok in editor and webplayer. However, when I try the android build, the mini map camera keeps blue (the color of the background).
My settings are : forward rendering, no occlusion, no image screen effects.
My device : Samsung SM-T110 tab 3 lite, android v. 4.2.2
Unity 5.0.2.f1
Does anybody have any idea ?

thanks,
L.