Installed these updates on both machines (Intel @ 10.6.3, and G5 @ 10.5.8). Same problem on both. The installer hangs on installation and a message appears that it wants to fix the problem with Adobe pdf viewer Safari plugin. Clicking on either "continue" or "cancel" does not move anything and the message on repair setup rests on the desktop until logout/shutdown. Force quitting the installer does not remove it. However, the subsequent application launch after force quit shows that the installation process is being finished/repaired and the app opens up with a new version. This glitch happens with both scenarios: downloading the update through help menu or downloading the installer from Adobe site.
Shame on Adobe!

The same thing happened to me when I updated my main drive. Here's an anomaly for you:

I downloaded the updater and applied it to my clone with no issues. Go figure.

It does not like the startup disks...

Interesting. Once again I had a similar experience as with the previous updater (see Adobe Reader 9.3.1 updater woes) in that the standalone updater didn't work (I couldn't select the Reader version to be updated as v.9.3.1 was dimmed), but this time the updater accessed through the Help menu worked. I noticed during this and the previous update that any alterations to Reader, e.g., adding the version number to the name, give the Updater indigestion.

I think, my problem is that I do not have the pdf viewer plugin installed (it never worked for me). Therefore, the installer always tries to "repair installation". This is where the update hangs, fortunately, after the actual completion of the install process judged by the functionality of the app afterwards. You probably have this viewer installed and it can proceed in a normal way. Looks like Adobe wants to control everything in the process. Not too smart, especially given the fact that the plugin is unreliable. I would love to have it worked (it is definitely superior to Schubert's in functionality) and am so angry that it does a beautiful job under Windows but not under OS X.

That happened when I ran the installer on my boot drive but not on the clone. BTW, I agree about the plugin. I switched to Schubert because the AR plugin would often cause Safari to hang when I downloaded PDFs.

Same problem here, except that I don't even see the message about repairing the installation. The installer just plain hangs, no message, no error, just sits there and never completes.

Adobe seems to be having some serious quality control issues these days.

I applied it without issue (I think), but I have no idea why I enjoyed that success.

When I first read of this issue, I thought I might need to install via the Safe Boot mode, but that proved unnecessary.

Now, I almost wish I had a problem so that I could exercise my Safe Boot postulate.

I didn't have any problems either with updating, although I continue to use the Adobe browser plugin without any significant issue. In my business experience I still come across pdfs that Preview (in 10.5.8) munches on.

I was finally able to update Acrobat Reader, though it took 4 tries and 5 reboots. After the first try, when the installer would simply hang forever with no warning message, I started seeing the "repair items" dialog--but the dialog window could not be selected and none of the buttons in it would activate. Each time this happened, the installer would lock up solid--not even Force Quit worked. Finally, after rebooting and re-running it and rebooting and re-running it, it simply worked. No clue what made the difference, or why it didn't work the first three times.

I used to be a huge fan of Adobe. These days, not so much.

There is a nuance! It is hard on Mac users. On PC it works (and worked) fine...
We should sue Adobe for platform discrimination.