I am having this same problem with a Netgear WPN824 v3! I have contacted Netgear, Verizon, Comcast, and Motorola. None of them can tell me what to do with the phone. Did no one think their troublshooting through before the release of this phone?
I dont know about the default browser, as I dont use it much because of lag issues. Try downloading Dolphin Browser from the market. When ever I have gone toa website with a bad cert it has prompted as you described above. It should fix your problem.
@delpstev - I don't think this is a browser related issue. The WiFi connection is not getting configured properly. Did you ever get prompted to create a password for certificate storage? Go into your wifi settings, touch and hold your work network entry and choose Forget Network. Then try connecting to it again. You should get prompted to create a password for certificate storage. Once you do that you should get prompted for settings including user ID and password.