Somehow I keep hitting a shortcut key (or something similar) that enables the input of accented text. Whenever this accented text mode is enabled, pressing ' doesn't respond immediately; instead, the ' key is remembered, so if I press a vowel after that, I get the vowel with an acute accent mark, and if I press any other key, I immediately get an apostrophe followed by the other key.
I don't want this to happen. It's very annoying. How do I disable this mode?
I've seen this behavior in Firefox, Pidgin, and Outlook. It apparently happens on a per-application basis, and restarting the application fixes it. I checked Windows 7's "Region and Language" control panel and didn't see anything relevant (although I'm not intimately familiar with all of those settings, so I may have overlooked something).
Edit: This is apparently not the same thing as changing keyboard layouts. I removed all non-U.S. keyboards from my keyboard control panel and am still seeing this behavior, and pressing LAlt+Shift (which the keyboard control panel lists as my "between input languages" shortcut) does nothing.