Client Problems

This is the second time in the last 2 hours that I have tried to get the client up so I can play. Every time I open it up it has to go through "Calculating differences, files scanned". It very frustrating when I have to wait for that to be done which takes about 2 hours to complete. It only just started happening over the latest patch and wondering if I can get some insight on why this is happening and if Riot is doing anything to fix this annoying whatever it is.