Zvirus
I have faced similar problem with my Fluval 205, but I figured out simply solution for this. If this will happen again, then remove gasket from the cover, dry it and put some cooking oil on it. Fit gasket back to the cover and cover should fit very smoothly to the filter. This works great for my filter, and I am doing this every second time when openning my filter. Hope this will work with your filter as well.
I agree about ribbed hosing in Fluvals, they are a bit of nightmare.