Two issues with Mitsubishi 734 input menus

I have two problems with the input selection menus on my 57734 DLP.

1) The *734s allow the inputs to be assigned names from the setup menu. For most of the inputs the options are "Cable Box, Camcorder, DVD, DVD2, DVR, Game, HD Disc, Satellite, VCR, PC, On/Off (ANT 1/ ANT 2 only) and Off (HDMI only).

For some reason, my HDMI-1 input only allows the choices of "DVD" and "Off".
I found that if there is active video connected to HDMI-1 it will not change the name at all. When I unplug the input, I can change between "DVD" and "Off".

Does anybody know how to work around this? I would like to connect my DVR to HDMI-1 and give it the right label.

2) Input-3 is unavailable. The connections are available on the front of the TV and are labeled "Input-3". On the Setup screen for assigning inputs, Input 3 is grayed out. I can't select it or change it. The manual mentions nothing about inputs being unavailable. What am I missing?

Does anybody still have a '734?

Please let me know if you can change the name of HDMI-1 input to something other than DVD, and if you are able to use Input 3 on your set.

I'm not sure if this is a component failure, or some strange software issue that might be fixed through a special procedure or menu setting.

GEP, thanks for the reply. The HDMI-1 input is not connected to a Blu-Ray player - it is connected to a Sage HD-300 media player.
However I will try disconnecting the HDMI cable, turning the input off, then plugging it in again, and then setting the name. Maybe I can "fool" it that way.

Regarding Input-3, I do have an input cable connected to it. It is not a matter of changing the name, but the input itself is grayed out cannot be selected. When I move through the inputs in the setup screen, it just skips over Input-3.