Dropped or Missing Keystrokes in IE 7 or 8
TIP: If you’ve recently upgraded to IE7 or IE8 and found that your keyboard is suddenly dropping characters when you compose a new email in gmail, you may be experiencing a problem due to the Adobe Shockwave Flash plugin. I recently got a new laptop with Windows 7 installed and was getting very frustrated with this problem. Unfortunately, online posts about the issue didn’t address the problem directly. In most cases, users were instructed to disable all plugins and see if that fixed the problem.
In my particular case, I simply disabled the Adobe Shockwave Flash plugin and the problem went away. I would note, though, that I only experienced the issue in gmail when I was composing a new message or a response to an existing message. Otherwise, IE worked normally.