one way anova vs. multiple comparisons

#1
I'm using matlab to study significance different in mean for deviation in the thre directions 8vrt, lng and lat). with one way anova i get no significance (0.0532) but with multiple comparisons i get significance between lng and lat directions. when i apply anova on just lng and lat i got significance (0.0006) how can it be possible?
 

hlsmith

Not a robit
#2
Do you control for multiple comparisons in the subsequent pairwise comparisons (adjust your level of significance to account for changes in chance)? Are the subsequent comparisons t-tests?