you could check the following: ;W|kc</R*
|T#cq!
- if the surface/element tilt is too large Fwm$0=BXL
i Ad&o`C
- enough analysis rays used? 9#E *o~1
x/QqG1q
- have you used Coherent Data option under Detector setting. 2g(_Kdj*{
#%,X),%-
Someone above was right about that the non-sequential mode only uses geometric rays but you could see inteference fringes using Coherent Data.