[Gameplay] Using Chat Bugs Keyboard Input

I have recently encountered a bug where using chat causes key input to bug, preventing me from using the store, leveling up abilities, and locking my movement into the attack command. As you might expect, this effectively removes me from the game. The only way to, temporarily, rectify this issue is to restart League, which doing so in a match seriously puts me behind, potentially throwing the game. It also prevents me from recalling.

I use a MacBook Pro:

• Processor 2.66 GHz Intel Core i7
• Memory 4 GB 1067 MHz DDR3
• Graphics NVIDIA GeForce GT 330M 512 MB
• Software OS X 10.9.5 (13F1066)

Edit: Changed title to better fit the board's reporting criteria.