Unless I'm missing something, you had Smyrna + Bulgaria --> Constantinople. Smyrna got attacked by someone other than the target of the supported move (in this case, got attacked by Syria, who isn't Constantinople) and so that cut the Smyrnian support. Without that support, it was Bulgaria --> Constantinople, a draw.

thanks alot, I really was convinced support could be kept alive using suppholds.

One thing to notice is that support is not cut if the supporting unit is attacked from the province he's supporting into, and is not dislodged. This is pretty difficult to explain, lots of stuff in that sentence. But take the following situation:

There is a French army in Paris, and German armies in Gascony and Burgundy. If Burgundy attacks Paris and Gascony supports, and Paris has no support hold from anywhere else, the attack will go through and Paris is lost, even if Paris goes to Gascony. He can't cut support aimed at himself.

If there's an army in Brest, and Germany does the same attack, but France attacks Paris-Gascony supported by Brest, Paris will succeed and force Gascony to retreat, but since he left Paris, Burgundy can walk into Paris.

However! If there is another French army in Picardy who moves to Paris... I'll repeat the moves first.

Germany has armies in Burgundy and Gascony. Burgundy attacks Paris, Gascony supports.
France has armies in Paris and Brest. Paris attacks Gascony, Brest supports.
Picardy moves to Paris.

Now Gascony's support is cut, despite the fact that it was Paris cutting support into Paris. Dislodging trumps anything. Burgundy will bounce with Picardy and Paris will not be lost, because with Gascony retreating, Burgundy now has only 1 strength.

A lot to take in and hard to explain, but I hope that makes it clear. Is that a Swedish name, by the way?

Oh, I forgot the main reason I went off on that long tangent. I think you may have seen an instance of this rule, and misinterpreted it. Let's take another(!) variation on this example:

French armies in Paris and Brest, just like before.
German armies in Gascony, Burgundy, but now also Spain.

Paris attacks Gascony, Brest supports.
Burgundy attacks Paris, Gascony supports.
Spain supports hold Gascony! <- the kicker.

Since Gascony is not dislodged, Gascony has a support hold from Spain, Gascony still supports Burgundy into Paris! So Gascony stays and Paris is lost.

I think you may have seen one of these situations, easy to miss for a new player.