New user needs help!

I created a song in BB, (latest version), that I want to create the .wav for. I want a 4 beat count-in with the side stick audible on the .wav. When I create the .wav, the first bar seems to be truncated. I think I tried every combination of options possible to no avail. I'm sure it's something I overlooked, because this is the first time I have had this particular problem. I'm not very proficient at editing the .wav I created to replace the missing bar yet, and I really want to let BB do it's thing and it will be perfect.
Also, is there a tutorial for editing waveshapes available? (I didn't have time to look for one but I know that it would make my life easier.)
I am using Vista HP on a new laptop, which I don't believe are the problem here since I have not had this problem with other .wav creations.
I have a gig Saturday and have to solve this asap. All help is appreciated.
Thanks.

Doug