Calculation of FDR-corrected p-values

Hi there,

I'm trying to calculate FDR-corrected p-values from the p field in my ROI.mat file. The p field in this file contains p-values which are equivalent on each side of the diagonal, as expected. However when I compute the FDR-corrected values for some reason the corrected p-values differ on each side of the diagonal (I've attached a screenshot).  

I'm using p_FDR=conn_fdr(p_uncorrected) to compute the FDR-corrected p-values.

If anybody has any thoughts on the values might be different on each side of the diagonal I would appreciate it!

Alex