I have received an error related to gnome-keyring-pkcs11.so not being found. More information on this problem is described in the following thread:
http://askubuntu.com/questions/127848/wine-cant-find-gnome-keyring-pkcs11-so
The fix is to download the needed 32-bit library (easily done via getlib) and then create the needed symbolic link:
wget https://launchpad.net/~jcollins/+archive/jaminppa/+build/1482994/+files/getlibs_2.06-0ubuntu1%7Eppa2_all.deb
sudo dpkg -i getlibs_2.06-0ubuntu1~ppa2_all.deb
getlibs -p gnome-keyring:i386
sudo mkdir /usr/lib/i386-linux-gnu/pkcs11
cd /usr/lib/i386-linux-gnu/pkcs11
sudo ln -s /usr/lib32/i386-linux-gnu/pkcs11/gnome-keyring-pkcs11.so
I should add that this doesn't seem to have much effect on reducing or solving any other issues we have with running Diablo (which is why I didn't add this in the tips/tricks section). This just removes on error that showed up consistently when launching the game.