hi there, I've been having some trouble with my wifi locking up on me while connected to any network. The icon in the top right of the screen says it's connected but I cannot access any web pages or complete any wifi related tasks. When i try to turn off the wifi and reconnect the icon remains the same. Essentially to fix the problem I have to put my mac to sleep by closing the lid and reopening it. Then I can turn off the wifi and reconnect properly. Connection times can last anywhere from 4 minutes to about an hour but without fail the connection will drop and freeze up again. This problem has been consistent through 2 or 3 operating system upgrades as well. Any help would be appreciated. Thanks!