My mac is only showing a blank black or white screen!

We have had reports of this occurring on the macs when using Safari, Google Chrome, and Firefox, but particularly when using Firefox. A reboot seems to always correct the issue. We have had some reports that clearing the browser cache will correct this, but we have not been able to verify this yet. This problem seems to impact Mac users using Firefox most often, enough that we recommend Mac users access our service via Safari. Alternatively, if you experience this problem more than once, you can switch to using a desktop vnc client to do your testing. With the new integration between Safari on the mac and the screen sharing application built into Mac OSX, this is a popular option.