Problem commenting

Is anyone else having problems commenting on other blogs? I find myself having a difficult time. Mostly whenever I write a comment I have to write it twice because the first time I publish it it just disappears. The second time I'm prompted to prove I'm not a computer by typing out those jumbled letter number things. I find myself unable to comment at all on a mobile device, which is annoying since I primarily use a tablet. I'm just wondering if anyone else has had this problem and if so any suggestions on how to fix it?