yep, another evergreen post.anyway I never has issues until I broke my 2000ml flask and got a new one. This one has a dome shaped bottom. The stir plate is a comp fan kit type. Are there flasks that just don't work? Like mine? Actually as I'm writing this I do see one stir bar manufacturing site the says a flat bottom works best. I'm looking at a bigger stir plate anyway. One for 5000ml. I'm looking at the "stir plate 3000". Or maybe the "black max". Anyone have one of these?