You might want to check the .msi link on your distribution page for Flash Player 11.5.502.149.
It's the exact same size as the .msi for 11.5.502.146, and when test deployed via SCUP DOES NOT overwrite version 11.5.502.146. It appears the link is still pointing to the outdated .msi, which fails to meet my needs in insuring security of my clients.
The MSI is 11.5.502.149; the digital signature date is the same as the EXE file (February 02).
Check that you do not download a version that is cached somewhere on your corporate network.