The army periodically steps in to remove corrupt officials, either at the behest of the king or the judges who have decided that the corrupt PM (the sister of the previous corrupt PM) ought to toddle off.
Thailand has a problem with the working classes being numerous and voting in characters like Shinawatra - the middle classes, backed by the king and the army don't like this as he and his sister were quite corrupt.
Yet, the middle classes have a problem of compassion - there isn't a centre-ground candidate which tries to talk to the poor and the middle-classes, bridging the gap and retaining order.
Every time someone who speaks to the poor, like Shinawatra (who basically bribed them), is ousted their supporters are (rightly I suppose) a bit miffed and like to cause a bit of a roadblock.
It'll sort itself out shortly, as it always does.