Just an FYI, we use a very similar setup except we use two MS LifeCam 3000 HDs.
We had a few "panic" moments on the field where we though the feeds weren't working, but for some reason it took a long time for the SmartDashboard extension to pick up and start displaying the feed after the robot was powered on on the field.
We would stand there staring at two pink screens until just seconds before the match started, and the feeds would come alive. They always did without fail, but it was nerve-wracking.
We kept the RPi set up on DHCP, with a hostname of "raspberrypi" - which is how we addressed it in SmartDashboard. We broadcast over ports 5800 and 5801. FYI, HTTP traffic is actually broadcast over TCP, so that restriction is not the issue.
I think it is just a time-out/retry delay with the SmartDashboard extension being a tad too long.
Just before our matches, if we were really nervous, we would open a browser on our DS, and navigate to the MJPG Streamer web interface (
http://raspberrypi:5800 and
http://raspberrypi:5801). This showed the streams working perfectly fine, even though the SmartDahsboard extension hadn't kicked in yet.
Hope this helps!