After reading all 40 posts, I just want to tell you to sell the 400D and just work on the FZ18 since you're so dependent on it. And seriously speaking, I'm almost sure you are not very clear with the controlling of the SLR you possess. People tend to blame it on their gear, but I'm doubtful of that.
Start from the basics. Learn the techniques. Read the manual. Do more Googling.