Mine threw it with both a spinner and a prop nut. It seemed the starter was giving too much force to the left, and breaking the stock saito nut loose just enough to sling everything off. I then tried the higley nut with the stock saito nut and an alum spinner, same problem, but this time just the spinner came loose. Got frustrated, and put the dubro nut on without threadlock (this was at the field), and after three flights, it would work loose and once came off with the starter. If I turned it over by hand, it wouldnt even kick back. So I just forced myself to get into the habit of handpropping it. Now with the threadlock, I'm sure I could nail it with the starter, but there isnt a need to do it. My gloved hand is way clear of the prop by the time it starts turning over to compression, and will usually start on the 1st or 2nd flip. I do have a bit more of a hassle after the engine is hot. I dont get enough fuel into the line/engine, and it takes a few more flips (thats my fault, not the engine's)

The 150 and even the 180's do have a reputation for prop slinging, and alot of it is due to too lean of a low end or trying to start them when they are fairly dry. It starts a viscious cycle of firing forward a turn, then firing backward a turn, then forward a turn, then backward a turn. Eventually somethings got to give, which ends up being the prop nut,spinner.

Just remember, when handpropping, use a glove. It will definately save you alot of grief in the long run.