I first noticed the problem a few weeks ago, maybe as much as a month ago. There is a very noticeable yet inconsistent delay between key inputs and the character appearing or the cursor moving. Interface elements such as the pop-up prompts for URLs and such also stutter and lag upon opening. The problem has persisted through multiple reboots and is consistently bad over time, and is exclusive to QQ's reply input box. I use Chrome, on Windows 7.