Triggers Not Cascading

Here's my table setup:

tblSteps:
StepID int IDENTITY
ParentStepID int ALLOWSNULLS
OtherID int
Amount money

tblOther:
OtherID int IDENTITY
Amount money

Now, I have a trigger defined on tblSteps:

Code:


CREATE TRIGGER tgrUpdateAmount
ON dbo.tblSteps
AFTER INSERT, UPDATE, DELETE
AS
BEGIN
DECLARE @Amount money
SET @Amount = ISNULL((SELECT SUM([Amount]) FROM inserted), 0) - ISNULL((SELECT SUM([Amount]) FROM deleted), 0)

IF (SELECT [ParentStepID] FROM inserted) IS NULL
BEGIN
UPDATE tblOther SET [Amount] = [Amount] + @Amount WHERE [OtherID] = (SELECT [OtherID] FROM inserted)
END
ELSE
BEGIN
UPDATE tblSteps SET [Amount] = [Amount] + @Amount WHERE [StepID] = (SELECT [ParentStepID] FROM inserted)
END

END



What this code basically does is this: if you update the amount of a Step that has a ParentStepID, it will take what was addded (or deleted etc...) and update it's parent with the added amount. If the Step does not have a ParentStepID, it will take the amount add add it to the Other row it corresponds to.

Here's an example of some test data:
tblOther:
OtherID: 1
Amount: 0

tblSteps:
StepID: 1
ParentStepID: NULL
Amount: 0
------
StepID: 2
ParentSTepID: 1
Amount: 0

If I update the Amount to 100 for StepID=2, it also updates the amount for StepID=1. If I update the amount for StepID=1, it also updates the amount for OtherID=1. However, when I update the amount for StepID=2, it does not cascade up to the tblOther level (e.g. Updating StepID=2 should update StepID=1 which should update OtherID=1, right?)

Basically, the trigger isn't cascading. Can anyone point out what I need to do?

Thanks