I am having the same problem! :(
I have the following line in my program:
MessageBox.Show("There is a problem with your data")
And a MessageBox does show up, but there is no text message or OK, label on the button. BUT, it only doesn't work on some machines, not all machines. i.e. on my computer at home, I get no text, but with the computer in my office, the text does display.