CallVB executed twice: In the logon script I use a CallVB statement. The called VB method displays a popup with system specific information. This works fine. But I am facing a strange issue: if the user is already logged on to the system and tries to login again to the same system the prompt gets generated again. Which should not be the case ideally, as I have called the function only once. What could be the reason?
The script for the logon screen is processed again when the popup is shown, since SAP always sends all screens including the underlying screen(s) if one or several popups are active. To handle this case use the statement

if not Q[inactivescreen]
  CallVB ...