Constant Game Crashing [CRASH]

I've sent many bug reports over the last few weeks because my game has been having problems with crashing, i have redownloaded the game at one point and thought it was fine but over the last few days i have been disconnecting from games repeatedly until the end of the game, i ended up getting 5 20 minute q's for my dc'ing which I've already gotten through. I don't really mind the q's I've already gone through but would really like to not have to do them again, is there any ways of handling this that i should know about? in all my years on the game its only happened the last few weeks. (by the way I'm playing with 200 - 300 mbps so i don't think its a connection problem)

Thanks for any feedback, see you on the rift.

(edit:) More details: The crashes im experiencing seem to happen at random but when they do happen its consistently through the game every minute or so and dont stop until the game is over, i dont remember the other times who i was playing but i was playing karthus in the last game it happened in

As for how to produce this I just join games and it happens not sure whats causing it