I have installed XSI DC several times - even rebooting XSI in between. I cannot accept the EULA because it is never displayed. What could be going awry here?
You don't say whether you are using the GUI or the command line.
If it was the command line, the probabilities that something is wrong or misplaced are lower, thus we will asume you are using the GUI
(c)XSIBackup-DC's GUI is based on nCurses, thus, it works on any SSH terminal. We can't fit all options and buttons in a classic bare 80 characters wide window though. You need to set your terminal to work in a graphic environment. This is how most SSH clients work by default, like Putty (our reference tool in Windows).
Nonetheless, if you use some basic SSH terminal software, you may be constrained by its reduced dimensions, such as that things just don't fit on your terminal window. This can cause from things not showing up to windows being printed partially on the available window size. Just stretch your window size.
If you are working in a Windows desktop, just use Putty, you don't even need to install it and it will work out of the box.
If on the contrary you are using Linux, remember to export the variable below.
So that the terminal will behave in an X way.