AIR seems to install but won't install any AIR apps

I installed AIR on Windows 7 64-bit Enterprise Edition, and it seems to install OK (no error messages).  But when I go to install an AIR app (Yammer desktop in this case) it will not install the app and I never see the installer come up.  This is a new computer that never had AIR on it.  First I went ot the Yammer site to load the app there, as I did on my XP computer.  The install started, but hung up.  I was at work, so I let it sit for a few hours, but it was still hung.  I then rebooted and tried to install using the offline installer.  It seemed to install, but won't install any AIR apps.  I have uninstalled/reinstalled AIR and Yammer but no change.  I also tried uninistalling using the MS FixIt utility, but no difference.  AIR seems installed but if I go to the Yammer web site, it tries to install AIR again.  Log below.

[2012-02-29:10:40:34] Runtime Installer begin with version 3.1.0.4880 on Windows 7 x86

[2012-02-29:10:40:34] Commandline is:

[2012-02-29:10:40:34] No installed runtime detected

[2012-02-29:10:40:42] Relaunching with elevation

[2012-02-29:10:40:42] Launching subprocess with commandline c:\users\ti905568\appdata\local\temp\airadbf.tmp\adobe air installer.exe -ei

[2012-02-29:10:40:42] Runtime Installer begin with version 3.1.0.4880 on Windows 7 x86

[2012-02-29:10:40:42] Commandline is: -stdio \\.\pipe\AIR_1448_0 -ei

[2012-02-29:10:40:42] No installed runtime detected

[2012-02-29:10:40:42] Starting silent runtime install. Installing runtime version 3.1.0.4880

[2012-02-29:10:40:42] Installing msi at c:\users\ti905568\appdata\local\temp\airadbf.tmp\setup.msi with guid {FE23D063-934D-4829-A0D8-00634CE79B4A}

[2012-02-29:10:40:44] Runtime Installer end with exit code 0

[2012-02-29:10:40:45] Elevated install completed

[2012-02-29:10:41:04] Application Installer begin with version 3.1.0.4880 on Windows 7 x86

[2012-02-29:10:41:04] Commandline is: "D:\UserData\TI905568\My Documents\Downloads\Yammer.air"

[2012-02-29:10:41:04] Installed runtime (3.1.0.4880) located at c:\Program Files (x86)\Common Files\Adobe AIR

[2012-02-29:10:50:08] Application Installer begin with version 3.1.0.4880 on Windows 7 x86

[2012-02-29:10:50:08] Commandline is: "D:\UserData\TI905568\My Documents\Downloads\Yammer.air"

[2012-02-29:10:50:08] Installed runtime (3.1.0.4880) located at c:\Program Files (x86)\Common Files\Adobe AIR

Any help would be appreciated.

Tom