Problem with aircraft shading at night

Help please!There is a marked difference in the appearance of the selected FSX aircraft ( addon or fsx aircraft all appear dark ) compared to other a/c on the ramp at night.By day all aircraft are depicted properly, only a problem at night.Trouble is, I'm not sure which is depicted correctly ( see screenshot ). Obviously there's something wrong with the shaders of one or the other and any help appreciated.The other aircraft are My Traffic X.Windows 7 ultimate 64 bitSapphire HD 6950 graphics( I've tried Bjotes shader 3 tweak but it doesn't make any difference )Thanks