No income from vassal? Please help

[michaeljassonsklt]

Play as byzantine at turn 84, my empire stretch from Casarea to Genoa. Few turns ago i had war with Milan and France. I kick those Milanese's butt until they only have 2 regions left(Milan and Bern). Then one of their diplomat approach me and off a ceasefire with I pay tribute to the 7800 for 2 turns, but I offer them vassalage for same tribute and they accept. Next turn. I saw my income from diplomacy, it said it was 0. Next turn later, France also want a ceasefire from me but offer them vassalage with I pay them 10000 for 3 turns, and they accept. France have Marseille, Rheims, and Dijon region. But still no income from diplomacy section . Is vassal offer no bonus income for their parent nation? Any help wold be appreciated, and thanks in advance

[Aymer de Valence]

My main advice:

http://www.youtube.com/watch?v=8CP9dg38cAI

But in other news;

When you say 'diplomacy' income, do you mean tributes?

[michaeljassonsklt]

But in other news;

When you say 'diplomacy' income, do you mean tributes?

I think vassal will automaticly give money for their parents nation.
But yes, in diplomatic screen I see my vassal backrupt. I think because they at war with each other (france vs england, france vs milan, milan vs sicily. Both france and milan are my vassals, england allied to milan and france allied to sicily, a perfect coalition)

[John Doe]

Are your vassal bankrupt?IIRC you get half what's left in their coffer at the end of their turn, half of 0 is still 0. You still get the money from trade rights though.