Heroes 5 Guides

Was the manual for 3.1 translated?

No. But there were translation errors, at least in the Russian version, for example, regarding the skill "Undead Protection from Magic" (it's unlikely that the mechanics changed from 3.0 to 3.1 in this specific instance).
Although, maybe I'm wrongly blaming the translators, and the error crept in even earlier, at the stage of the English version?
I haven't studied the Russian version of the manual for 3.0 in detail; it's still not as informative as 3.1, even without taking into account the changes.