New Post: Get Reply to Specific Tweet

Hi Linvi,
I use

bool getRecursiveReplies = true;
IEnumerable<ITweet> discussion = Search.SearchRepliesTo(SelectedTweet, getRecursiveReplies);

and it's working, but in a strange way: sometimes It gets all tweet in a discussion and sometimes not (or not all tweet):
It's seems to depend on how old are replies: is it possible ? How can bypass this problem ?
Thanks a lot!

Alex