fingers crossed this works! as you can see we haven't bothered with the bottom one on the front side because it's very sheltered with the extension and the windbreak
not had that problem so far. i think you just need to make sure that the canvas is taut to avoid that which we did find quite tricky the first time, especially on the bed end.
The problem when I got mine was that the previous owner had only used it once and had adjusted almost every pole that could be adjusted which made it very hard for us to erect the 1st time.
Since then, it has been trial and error but almost got it down to a fine art now.