I have also been having problems installing Flash Player 11.6.602.167 on my Mac (OS 10.7.5). I decided to try uninstalling, then re-installing after an online tutorial stopped working to see if it was related to Flash Player. I am able to download OK, and I double click on the icon to install (with Safari shut). It starts to install, but then stops at 38% and says installation failed. I have tried this several times and the same thing keeps happening. I have been through the Installation for Mac Issues page without success, including trying to install via Show Package Contents.