when something changed in the q3 sources (added unicode support?) the console mapping on the keyboard actually got assigned to a character instead of a specified key, like it was in the old q3, so it's no longer accessible on some layout (eg: the italian one).
this is not a problem, anyway, just open /Users/youruser/Library/Application Support/OpenArena/baseoa/q3config.cfg with TextEdit and search for "toggleconsole", then change the key assigned to it.
for example with
the console will appear when the "a" key is pressed.