Xinmei's digital signature scheme and the scheme's modified version as proposed by Harn and Wang have been shown by the authors and others to be susceptible to several different attacks. The authors have since devised and presented a scheme that is impervious to the attacks that were successfully applied to the earlier schemes. It is shown in this paper that this new scheme and Xinmei's scheme are vulnerable to universal forgeries. Equipped with this attack and the earlier ones, general remarks about digital signature schemes based on linear errorcorrecting block codes are presented.