Can't install or update applications from SD card

[shorty82]

I apologize if this has already been addressed, my search skills are not perfect but I have looked for an answer on several different sites. When I try to install or update any application using a saved copy on my SD card, I can't. I have the check box checked for allow 3rd party application, etc... The problem I get is that when I get to the installer and it has the buttons "Install" or "Cancel" I can't select install. The only thing I can select is cancel. I have tried to clear the different caches, I have reinstalled cyanogen over the top of my current rom, I have rebooted several times, etc... It stinks because I can't install or update any applications that are not available on the market. The market still installs without any issues. This issue is not related to a single application, all applications that I try to install from my SD card have this same issue and they are not corrupt because I have known good copies (previously installed from SD card) that have the same issue.