Thanks for your advice.
On the subject of glitches, I just had a full Wi-Fi signal without access to the internet. I turned off AirPort on my computer and turned it back on again. Like before it worked again after.
Due to this, I checked the console:
05/09/2008 20:17:36 SystemUIServer[111] Error: airportd MIG failed = 1 ((os/kern) invalid address) (port = 63495)
05/09/2008 20:17:44 kernel WLC_E_COUNTRY_CODE_CHANGED
Are two glitches in to days too much of a coincidence?