I think, you are using VB comm object in a wrong way. I have bean using it for a long time, but I had problems at the begining too. Usualy, I read data from buffer symbol by symbol. to do this, you have to configure MSComm1 in this way:

MSComm1.RThreshold = 1
MSComm1.InputMode = 1

(and other settings as boud rate, and so on)

Then double press on MSComm1 object and write subroutine like this:

Private Sub MSComm2_OnComm()

your_recived_char=MSComm1.Input
End Sub

this soubroutine is something like serial interupt. Using this method, you can't miss any simbol.

Happy programing
P.S. If you still have problems, e-mail me, and I'll send you working sample code ;)