A couple of weeks ago, the original "Messenger" contact entry for them was removed from everyone's lists. This means if they never talked to you using Skype, they've just disappeared.
kupoexe, please get in touch. Skype has removed you because of this. Outside of dA I've lost a couple of other friends I speak with regularly because they used the MSN protocol on alternatives like Trillian, or the web chat feature on Outlook.com. They're just gone.
Everyone, we seriously need to look for a new chat program. Skype has had problems delivering messages correctly for the last year and now it's removing our contacts - deliberately. This is a complete failure of the two most basic functions a messaging program is meant to perform.