When using the 'fixed' font with xterm, the bold version of it is unreadable. Note that the same font setting (fixed, bold) in rxvt or gnome-terminal looks correct.
Hmm. Seems to look ok on my machine.. perhaps I'm not set up the same tho.. Can you provide me with the exact steps to duplicate the problem?
I run 'xterm -fn fixed', my shell is 'zsh' with the prompt set as PS1='%B%n%b@%m (%B%~%b%)%!%# ' The bold part of the prompt is unreadable when using xterm, but it is fine with rxvt.
I consider this a configuration problem rather than a bug. If you play around with font settings, you should be able to get it to display.