Some of the links on this forum allow SMF, at no cost to you, to earn a small commission when you click through and make a purchase. Let me know if you have any questions about this.
I had the asame issue. The cheap vinyl cover that comes from Brinkman is not very good, and rips far too easily.
I replaced it with a "WeatherReady medium round grill/smoker cover" and was very happy with the product. Its made like a good grill cover, and seems very strong. It measures 22x22x32 and covers the smoker nicely.
Got mine thru Amazon.com here is the link to the cover.