Comment # 4 on bug 913555 from V��t��zslav ������ek

(In reply to Neil Rickert from comment #3)
> That's not a bug.  It's a feature.
> 
> The gpg2 developers have decided to exclude pgp2 keys because they use md5
> hashes which are considered insufficiently secure.

That's correct.
gpg will reject signatures made by MD5 unless --allow-weak-digest-algos or
--pgp2 is specified.

With theses options, the failing key will be imported.