#17 WaitForDoCan't call method "frames" on an undefined value at

[Anonymous]

Error: "WaitForDoCan't call method "frames" on an
undefined value at C:/perl/site/lib/win32/sam.pm line
303" keeps occuring when i run the code below:

The above error keeps occuring when the while loop has
executed 56 or 57 or 58 times (Error keeps on occuring
in the range of 55th - 58th run.)
----------
use strict;
use Win32::OLE;
use Win32::SAM;

#variable declartions
my $URL = "http://webPage";
my $seconds;
my $vUsers;

print ("Define # of vUsers: ");
$vUsers = <>;

#####PUT LOAD ON AUT#####
while ($vUsers > 0)
{
# Step 1: open AUT
StartIE();
$seconds = Navigate($URL);
print ("OUTPUT MESSAGE: The page $URL took $seconds
seconds\n");

# Step 2: Login
SetEditBox("txtName", "parvinder\@abcdef.org");
SetEditBox("txtPassword", "1234567");
ClickFormButton("Login");

$vUsers--;
}

exit 0;
-----------

I'm testing a web application for load test. In
particular i'm testing the login page (nothing too
complex).

I could be reached at qtptester1@yahoo.com.
Your help is greatly appreciated!!!!!
Thank You.