/usr/share/texmf/xdvi/XDvi has the line
It should be changes to
(at least for the US version of RedHat).
BTW, bug report #492 states that this problem (wrong default paper
size) was fixed for dvips, but does not say if it was fixed for xdvi.
I have verified this to be as ws reported and is being passed on to a
developer for further review.
This change request has been made. No other files appear to have
a4 paper sizes included in the config files.