I've got two of every race, 1 male and 1 female, for some reason both male and female Undead characters do not have portraits automatically generated.

Hey there,

In game, undead players are categorized as being part of the "scourge" race (prolly a leftover from WC3 or to differentiate from undead mobs)
Usually, stpain put a workaround in the code in the form of if character.Race:lower() == "scourge" then race = "undead"; for them to be correctly categorized for Guildbook
Seems in this case that the workaround either failed or wasn't there