I get a bit of rain pooling in mine, but a slight puff of wind will dump it and it never gets much more than a couple cups.
My slide awning is something like 8-10 feet long on the living room super slide.
I think Lou is on to it with the tension, your bending rod just doesn't sound right to me...
2011 Flagstaff Classic Superlight 831RLBSS "Atrium slide"
Husky Centerline Hitch
1998 GMC Sierra SLE K2500 6.5 Turbo Diesel