WinWaitActive?

I have a job that runs as a scheduled task, but because I have other apps runing on the server, it seems to stop at the login prompt.
When you click on it, it then proceeds to run the job without problems.

This is the part of the script that causes the issue:

;Sign In
WinWaitActive("Dispatch Manager Sign In")
Send($Pwd & "{Enter}")
WinWaitActive("classname=TMessageForm")
;MsgBox(0,"Purge Disabled Records","TMessageForm")
Send("{Enter}")
; ExitDM()


I tried changing the second WinWaitActive to WinActive, but it still fails
If I change bot to WinActive, it does not carry on with the job

What command do I use to force the login prompt to always be active, no matter what other apps are running?