The last weeks I've experienced that  names in my tree can give a match to all of its sisters or brothers in additional. 

And the match can be listed twice. Usely I most reject most of the matches because of this.

Do any one else have this problem? 

Usually if the match is repeated it's because either you or the other person has the name twice on their tree/site. As far as matching a person to their siblings, myheritage has never really seemed to give a satisfactory answer, and it's a situation that's gotten a lot of complaints.