Optical Cavity at resonance

[tornibue]

I need some help with my attach FRED simulation. Attach is a FRED file, that I have been using, trying to simulate an optical cavity operating at resonance.
According to theory (see Anthony E. Siegman, “Lasers” , University Science Books (1986), pp 413-427), when the reflectance on the first surface equals the reflectance of the second surface multiply by the round trip losses in the cavity, there should be no reflected ray from the first surface.
If the reflectance of the first surface is made to be equal to 0.9 and that of the second surface to 1, then the round trip losses should be equal to 0.1. Using a cavity of length 1 mm, that should give an absorption coefficient of 0.05268 mm-1.
Using this as the cavity in FRED and simulating, I do not have zero intensity of the reflected ray from the cavity first surface, as required.
Also, I realized that, turning the absorption on and off, do not affect the intensity profile of the reflected ray from the first surface, as would be expected.
I wish to find out, why do I have these discrepancies in my results?
Also, am I doing some thing wrong with my simulation?
Kometa