I worked this pattern and if the instructions are followed, it does come out right; I don't recall a mistake in the pattern. The pattern shows up more with a yarn that gives well defined stitches. I used cheap acrylic and cotton and both worked well for showing the pattern. Sue, you know what the correct terminology for that type of yarn is, it escapes me right now. Anyhow, it is in earlier posts to this thread.
Trust the pattern.
I should never overestimate my basic arithmetic skills.
I think the wool weight and type is important. I also got a less than "diamond" pattern. But in certain light it looked better. I also found that when the glove was on a hand the stitches pulled and looked more like moss st :(. Saw somewhere that it has to be knit tightly so I'm trying that too. Next project for this I will try thicker / coarser wool. The wool I'm using now is 8ply and quite "soft" (maybe that's the twist people were mentioning?). I think equivalent wool should have been 10ply. It's hard to do all conversions etc! I checked my gauge and it was right so I forged ahead. Although now that I think of it my rows per inch were a bit off gauge.