I have an annoying new behavior on my MBP 13" running Lion (10.7.4) that I don't know what I did to provoke. I am familiar with so-called visual bells in terminals, but I've noticed a similar effect happening in any window in my OS X session - not just in Terminal. I've researched this and there appears to be a setting in System Preferences -> Universal Access -> Hearing where you can enable a screen flash in place of an alert sound. However, this is unchecked on my system.
Any ideas how I can correct this? I'm going to seize out soon if I can't figure out how to disable it...ugh.
EDIT: In response to the comments/questions below, I have confirmed that the plist also shows this setting disabled. I'm not sure what the advantage to removing the plist file and logging out/in would be.
plutil -convert xml1 -o - ~/Library/Preferences/com.apple.universalaccess.plist|grep -A1 flashScreen <key>flashScreen</key> <false/>