ExecuteNonQuery() Not Giving Correct Affected Rows

 When I use ExecuteNonQuery() with the stored procedure below it returns -1. However, when i tried to get rid of the if/else statements and just leave one insert statement for testing purposes, ExecuteNonQuery() returns the correct affected rows which is 1. So it seems like ExecuteNonQuery() doesn't work when the INSERT statement is inside the IF..ELSE. Can anybody help me with this problem? I haven't tried using @@RowCount because I really want to use ExecuteNonQuery() to do this because I don't want to rewrite my DAL. Thanks in advance
 
-- With if/else ExecuteNonQuery returns -1

ALTER PROCEDURE [dbo].[SP_AddObjectContribution]
  @ObjectId int,
  @FanId int,
  @DateContributed DateTime,
  @Notes nvarchar(512),
  @ObjectType int
AS

BEGIN

  BEGIN TRAN
    IF @ObjectType = 2
    BEGIN
      INSERT INTO FighterContributions
        (FighterId, FanId, DateContributed, Notes) VALUES
        (@ObjectId, @FanId, @DateContributed, @Notes)
    END
    ELSE IF @ObjectType = 3
    BEGIN
      INSERT INTO FighterPhotoContributions
        (FighterPhotoId, FanId, DateContributed, Notes) VALUES
        (@ObjectId, @FanId, @DateContributed, @Notes)
    END
    ELSE IF @ObjectType = 4
    BEGIN
      INSERT INTO OrganizationContributions
        (OrganizationId, FanId, DateContributed, Notes) VALUES
        (@ObjectId, @FanId, @DateContributed, @Notes)
    END
    ELSE IF @ObjectType = 5
    BEGIN
      INSERT INTO EventContributions
        (EventId, FanId, DateContributed, Notes) VALUES
        (@ObjectId, @FanId, @DateContributed, @Notes)
    END
    ELSE IF @ObjectType = 6
    BEGIN
      INSERT INTO FightContributions
        (FightId, FanId, DateContributed, Notes) VALUES
        (@ObjectId, @FanId, @DateContributed, @Notes)
    END
    ELSE IF @ObjectType = 7
    BEGIN
      INSERT INTO FightPhotoContributions
        (FightPhotoId, FanId, DateContributed, Notes) VALUES
        (@ObjectId, @FanId, @DateContributed, @Notes)
    END

    IF @@ERROR <> 0
    BEGIN
      ROLLBACK RETURN
    END

  COMMIT TRAN

END
 
-- Without if/else ExecuteNonQuery returns 1

ALTER PROCEDURE [dbo].[SP_AddObjectContribution]

  @ObjectId int,

  @FanId int,

  @DateContributed DateTime,

  @Notes nvarchar(512),

  @ObjectType int

AS



BEGIN



  BEGIN TRAN


      INSERT INTO FighterContributions

        (FighterId, FanId, DateContributed, Notes) VALUES

        (@ObjectId, @FanId, @DateContributed, @Notes)


    IF @@ERROR <> 0

    BEGIN

      ROLLBACK RETURN

    END



  COMMIT TRAN



END