Fourth Shadowhand mode?

[F4LL0UT]

Hi, I won the Serious Unlce Sam challenge (finally - I almost went crazy because there weren't enough enemies' spawning the first time and I achieved like 492 kills).

From what I understand the reward should be a fourth mode for the shadowhand. But no matter if I continue the campaign or replay a previous level, I only have three modes. Did I missunderstand the meaning of the reward? Or has something gone wrong? Or is it just a special attack for a fourth mode that I somehow missed? Please tell me. This is really driving me nuts.

I'm playing the Polish release on version 1.1 in English language (at least I hope it's 1.1 - there's been some problems because I applied the wrong patches first <.<).