Secure Lockdown Chrome edition locks up computer on desktop, Alt-Shift-S does not work

I have 12 Kiosk Computers running Windows XP and Secure Lockdown for Chrome.  Today I had to "allow" an additional website for access.  After completing the task and turning Secure Lockdown back on, I had 3 computers that would just boot to the Windows Desktop.  I have Windows XP logging the user account used for Secure Lockdown in automatically.  I am unable to logoff and log another user in to fix it.  It is as though the computer gets locked down and then Secure Lockdown shuts off.  I have already wasted 1 client license as I had to re-image the disk to get it back, now I have 3 more.  Does anyone know what I can do to fix this?  I am unable to log in "safe mode" or anything else as it was all locked down.

Also, when this happens I am unable to remove the secure lockdown license. How do I go about getting the license back since I am unable to uninstall it?

To gain access to another account while SL was enabled, did you do the following as described in this article:

"If you want to bypass the automatic logon to log on as a different user, hold down the Shift key after you log off or after Windows XP restarts."

I've met similar problems with my client's kiosk computer. It's running Windows 7 Pro. We only have one account only. The computer is locked down but we can't even bring up Secure Lockdown panel. We are using Firefox as the browser.

There is a potential that if the system clock is set to a time before Secure Lockdown was enabled, the utility will not start after login. This can occur if the battery on the motherboard dies and the system clock gets set due to it. Look to see what the time/date is in the BIOS.

I was able to gain access after following the directions the Moderator posted, ""If you want to bypass the automatic logon to log on as a different user, hold down the Shift key after you log off or after Windows XP restarts."   Specifically since "logoff" was not an option I pressed down the shift key when the Windows XP splash screen appeared and it allowed me to log in as a different user.  I was able to go in and uninstall the license since I had to rebuild the image anyway.

I am still not sure why the lockup occurred but my theory is Symantec Endpoint Protection caused the problem.

My only other outstanding problem is reclaiming 2 licenses I lost from trying to troubleshoot on my own.