There seems to be a problem with the euro sign in gnumeric. I couldn't find a
font that made gnumerice display the euro sign (and not show the "currency" sign).
This is not true for the menus: if I insert the euro symbol in a cell, the
currecy symbol is shown. However, the undo line in the edit menu now shows the
euro symbol correctly.
Upstream as http://bugzilla.gnome.org/show_bug.cgi?id=103301