[OU] Opera on Windows using wrong font settings?

[Fred Bone]

Opera 9.23 on WinXPPro/SP2

I recently had to play around with (Windows) Display settings, 
specifically the setting for the "Message Box" font, and found that Opera 
is using this, rather than the "Menu" font, for the Menu.

Is there a good reason for this (which I am failing to see), or is it a 
mistake? and if the latter, please could it be corrected?