IWDatacapture.close(false) inconsistent behaviour

System

to work around an interwoven bug, we're got some FormAPI checking going on through the "onInit", to validate the user's role...if user is an author or editor, they'll get a pop up alert message, and want to immediately follow with closing the DCT...here's the function, nothing shocking, completely simple, and as mentioned to do in other devnet threads:

function ValidateAccess() {
var userRole = IWDatacapture.getRole();
if (userRole != "master" && userRole != "admin") {
alert("You don't have sufficient permissions to edit this dcr type.\nYou must be either a master or an administrator.");
IWDatacapture.close(false);
}
}

we reliably get the alert window for the author and editor roles...however we do NOT reliably get the DCT to close itself...the code hasnt' been changed in ages, and it does close itself, but only on some occassions, like when it feels like it, it's a blue moon on the 3rd tuesday of the month, the temperature is exactly 78 degrees, or I'm standing on my head...

anyone else experiencing this inconsistent behaviour???

thanks,
-Rori