This forums is read, Jesse and other riot staff comes through fairly often and the Wrenchman all call attention to specific issues when needed.
Additionally, this type of disconnect issue was just addressed with the last patch, so it's not off the radar either.
Specifically to your problem, if you can log on a smurf account and play without issue every single time versus your regular account, the most likely issue we see with situations like this is a slow or bad internet connection on the player's end.
When you level up your summoner, you build additional data that needs to be transmitted with the account, including champions, runes, statistical data, etc. On slower connections, the larger amount of data sometimes creates issues with timeouts and transfers which can cause disconnections.
If you're getting disconnected as part of a match (booted in game, or when you come back you have the option to reconnect) Please post your in game logs. Also, you may want to try running a netalyzr to test the connection.
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