Computer quirk - unable to comment

I love it when I'm about to comment on someone else's blog and then I realize that due to some quirk in the computer or network, I can't comment on this person's blog on my home computer unless I fully signed out of blogger on my work computer, or vice versa. Well, I forgot to do that, and now I'm stuck not being able to comment because I am taking the next few days off from work for vacation. The weird thing is that there are only a couple of blogs that this happens on - it must have something to do with how they are set up, etc., etc. Computers for me are kind of like the weather was to everybody before modern science - mysterious, powerful forces that I can try to take advantage of, but that are ultimately beyond my control and can turn on me at any moment.