"DC Proof does not work with Wine (Windows Emulator for Linux)"
Possible Solution:
Wine representative, Dan Kegel, wrote to me in December 2005 saying:
It looks like a problem with Wine's implementation of richedit....
I verified the problem, and filed bug http://bugs.winehq.org/show_bug.cgi?id=4058 against Wine....
I went a step further, and verified that the problem goes away if you drop a native riched20.dll [from the Windows\system32 directory?] into Wine's system32 directory. So now there's a workaround for the motivated user.
Thanks, Dan!