I have noticed this too, seems the software is trying to guess when you dont press long/hard enough and so it thinks it's an accidental press or something but it still shows the feedback as if you pressed it. I dont have an answer (my typing is waaay to slow for this to matter to me yet) but I can confirm I have seen this too.

 

I have had several issues when using the virtual keyboard. Hopefully they get it fixed with dec. 11 update.

 

I think that a lot of people are having the same problem. The main reason for this problem is that the virtual keyboard is not multitouch. So, your finger has to be removed completely from a key to register the next. I have noticed in my typing that the letter will be recognized, but will not register.

 

I had a really bad problem with this on my first phone and posted the same thing. At that time nobody else seemed to have the problem... or they didn't comment on it. I exchanged my phone and it is working much, much better. It still does occur but a lot less frequently. My first one I could barely type. It seemed that most words it put a space where I had typed a letter. If yours is really bad I would take it back because it definately fixed mine.