Where is my precious (gold) gone ?

[Herode]

Hi gentlemen,

for 2 turns at least (I didn't check before, anyway it is fairly recent), my treasury looks pretty low. This turn for example, I have stats such as
Total income : 1277
Upkeep : 698
Treasury : 359.
BTW : 1277 - 698 = 579, hence I expect to find 579 + (t-1) gold in my treasury. Am I wrong ? Is there any point I'm missing ?

No bad events this turn, and no event showing gold being stolen last turn.

NB : last turn, I also pillaged a province for > 1000 gold profit, but this gold never appeared in my treasury.