i had the same problem with sum static meshes that wouldnt light up properly and sum walls, heres what i changed and it fixed it for me, hope it works for u. if its a static mesh or if you have this option go to its properties and change it to
Display-bstaticlighting=false
also try changing the level properties, this can really help ur ligthing issues and it looks cool too! in Level Properties find Zone light and change it to this, it may seem dark at first but add lights and you will see the wondeful changes take place, (hopefully)
zone light-Ambient Brightness =10
-Ambient Hue =0
-Ambient Saturation =255
-Distance fog blend =1.000000
-Distance fog end =5000.000000
-Distance fog colour A=0
B=148
G=107
R=121
-Distance Fog start =3000.000000
-Dramatic lighting =1.200000
you might find that sum of these properties dont need changing.
also another good tip is too load up a different map that has the lighting effects you want etc.. and simply copy it hope this helps.
dont forget to rebuild after the changes to see the changes! and also you might want to make a copy of the mpa elsewhere incase you mess things up even more