Windows 32-bit Link:
http://download.macromedia.com/pub/flashplayer/updaters/cs5/win/AdobeAPE3_mul_AdobeUpdate.zip
Size: 5.81 MB
Windows 64-bit Link:
http://download.macromedia.com/pub/flashplayer/updaters/cs5/win/AdobeAPE3_x64_mul_AdobeUpdate.zip
Size: 6.11 MB
Macintosh Link:
http://download.macromedia.com/pub/flashplayer/updaters/cs5/mac/AdobeAPE3_mul_AdobeUpdate.dmg
Size: 12.7 MB
Description: This update fixes critical bugs and security issues which existed in Adobe Player for Embedding.
Release Date: 09/03/10

Any idea what conditions might prevent me from installing this on iMac with CS5?
Installer log says:
ERROR: No media information provided for removable source location
ERROR: Cannot iniliatize payload session
Hmmm
Hi John,
Have you tried updating via Help> Updates…? That uses a different mechanism and may get you past the errors (assuming you are running the downloadable installers linked above).
regards,
steve
Some CS5 updaters refuse to install from a mounted disk image. This is one of them. Copy the contents of the disk image to the local disk and try again…
nope still doesnt work