Problem with my machine

I am a little sad today. I've been sewing a ton with my new Singer machine. It runs great for all the basic stitches, but I have been having problems with the decorative stitches. I double checked the handbook to see if it was something I was doing, and everything was in order, but the machine was not running correct. I had to take it back to the store. I ended up trading my machine for the Brother Project Runway model. I was a little leery about buying a Brother sewing machine. I will let you know how the machine holds up!