Fed up with SP manipulation

I really think Betfair really need to rename SP. So often it never resembles starting price at all! Today I was having trouble getting filled on the favourite in the last race at Ascot. As you can see from the graph it went from 6's to 40's, Just before the 'off', which as far as SP is concerned is about 6 seconds different from the real off. It cost me around £140, which was annoying, but not much in the scheme of things. It's not me I am concerned about but I feel desperately sorry for people who got thumped on that or anything else for that matter. I took a risk, but knew that it should be minimal on a jumps race. I hadn't considered the impact that a difficult start from the favourite would make, especially when he was reluctant to jump. Another lesson learnt but I feel strongly the term "Starting Price" should be reviewed or people made more aware of the problems with this mechanism.