Windows 7 / GeForce GT 610
Short description of error
In the weight paint mode has a hot key that changes the value of the weight (W). But if to paint weights for bones (the bone is selected), then on key "W" that will be call the special menu for bones (and there is no way to call weight radial change). I think by default a key of change of weight there shall be not W (maybe ctrl+F or something else).