XPWhat version of windows are you using? Tooltips should work the same as any tooltips.I pushed icons (camera, help, etc) then tooltip any more do not work (do not appear).
In vain. It strongly reduces utility of the program. If it is impossible to make the alpha channel, it is necessary to make a choice of any colour of a background, or background image.There is no alpha channel.
And all the same tell why you have chosen N3xt-D, to me interestingly what it offers advantages to creation of similar programs. Why not OGRE?