Counter is generally working great, except one time where it randomly added a few hundred floatzel encounters during my Electabuzz hunt. I think I had pokemmo minimized at a time when I'd encountered a floatzel horde, and when I came back it had changed the number. I haven't been able to recreate it, so it's possible I forced it to get stuck in a loop or something.
Also, just FYI, I get this error when I try the data dump, but it's probably got something to do with the saving methodology you mentioned in a previous post.