Adobe has recently released a 9.1.2 update for Adobe Reader 9.1. You can download it from their FTP site here:
If you want to deploy the update to your systems, that are already running Adobe Reader 9.1, using your ESM software, you can use a command similar to the following:
msiexec /update “%~dp0AdbeRdrUpd912_all_incr.msp” /l* “%WINDIR%Adobe Reader 9.1.2.log” /passive
The 9.1.2 update includes changes made in the 9.1.1 update, so you can remove 9.1.1 from your deployment.