Kefir-strange texture

I have been using kefir for over a month now, with wonderful success. However, my last two batches have been strange. After it cultures, the kefir has been gelatinous. Kind of like when you are separating an egg white and the white wants to stay all together in a blob. I wonder if it is safe--did some other bacteria get into it? Anybody ever experience that or know why it is now like someone mixed Elmer's glue in? Thanks.