cannot connect to secure guest network

My company is pushing more of our work content to the iPad2 via internet connection to databases, etc. I work in a hospital as a vendor. The hospital has a guest network setup that requires authentication by providing your email address and accepting their terms and conditions. For a few months I had no issues connecting with the company provided iPad2. For the last month, I have not been able to get connected. I can work on my 3G connection, but most places I go in the hospital do not allow a 3G connection. The iPad sees the guest network, and is connected as indicated by the blue check mark. Additionally, my Android phone and Windows XP laptop connect with no problem.

The information the ipad is pulling from the router is:

IP Address: 172.22.80.149

Subnet mask: 255.255.255.0

Router: 172.22.80.4

DNS: 192.168.16.8

IP address is set to DHCP. HTTP Proxy is OFF. Auto-join and Auto-login are both on. I've tried it with Auto-login turned off too. The error message I get in Safari is: 'Cannot verify server identity. Safari cannot verify the identity of "securelogin.arubanetworks.com".'

I've tried forgetting the network and renewing the lease. I've tried resetting network settings. The hospital's IT department doesn't provide support. Currently my company's IT department is baffled.

The iPad is running iOS v5.0.1. Ipod touch CAN get connected by seeing the authorization screen, agreeing to terms and providing email.

Can anyone please help?!