How deploy updated MST?

[#1]

Hi all
We deployed Adobe Reader 9 to 50+ users using the supplied MSI and our own custom MST.  We have since discovered a problem which we can resolve with an update to our custom MST file.  However, we have tried to update the existing installations using the following command lines with no success:-
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:: Uninstall Adobe Reader 9
msiexec /x \\server\share\AdobeReader9\AcroRead.msi /qb! /norestart ALLUSERS=1 /l*vx C:\AdobeReader9uninstall.log
:: Install Adobe Reader 9
msiexec /i \\server\share\AdobeReader9\AcroRead.msi TRANSFORMS=\\server\share\AdobeReader9\ar9.mst /qb! /norestart ALLUSERS=1 /l*vx C:\AdobeReader9.log
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How do we apply an updated MST file to existing installations please?
Thanks
Scott

[#2]

Are you just using command lines for managing the deployment, or do you use AD to manage it?

[#3]

Hi James
We use LANDesk to deploy the batch file, as we have successfully for many MSI deployments.
Do you know how to deploy an updated MST file to existing installations please?
Thanks
Scott

[#4]

Hmm - not got any experience of Landesk - In Active Directory its straightforward.
Can't Landesk advise?

[#5]

Sorry James, should have mentioned that I am 99.99% sure LANDesk is not a factor here, it merely deploys what it is told to deploy, nothing more.  We proved this by running the install in a command prompt to eliminate a potential LANDesk issue.
We deployed Adobe Reader 9 using LANDesk the first time without any problems, we just need to update the installations with an updated MST (if that's possible?).  Well, assuming it's not possible, we updated the script to uninstall AR9 then install it again but with the updated MST file.  No errors when doing so, but the changes in the MST are not applied, in fact the old configuration of AR9 from the original MST are re-applied even though we uninstalled it (!).
So perhaps the new MST is not overwriting the old MST? 
Any help is much appreciated.
Cheers
Scott