2-way ANOVA and the post tests

Hi everyone :) I was wondering if you could help me with a question which should be simple... but the more I am trying to figure it out, the more confused I get :confused:

I am trying to see the effect of a treatment (so I have a control and treated group) at different time points before and after exercise on the immune system - I did a 2-way ANOVA (my placebo/drug groups in columns and the time points in rows; then I ticked 'each row represents a different time point'; on the multiple comparison tab I chose 'compare each cell mean with the other cell mean in that row' (to get the drug vs placebo statistics) and I did another comparison choosing 'within each column compare rows' (to get the effect of time/exercise on the immune system).
All seems good so far but then, when I check the Tubular results it tells me -
" Interaction" - significant (*)
" Time" - significant (***)
" Treatment" significant (ns)
" Subjects (matching)" - significant (***)
Then I click on the multiple comparisons tab and everything is not significant?

I guess it is a basic thing I am missing out and I can't explain to myself, but how do I get a significance in Treatment for example and then when I compare the Drug vs Placebo I see nothing?

Thank you in advance - any help is warmly welcome :)