I still cannot restart or shut down.
Hold the power button down until the screen goes black then restart.
Your profile indicates you have v10.8 installed but you posted in the v10.7 Lion community.
If you have v10.8 Mountain Lion installed...
Open System Prerferences > Security & Privacy then select the General tab.
Click the gold padlock icon to make changes. Yiou may be prompted for your admin password.
Select: Mac App Store and identified developers
Click the lock to prevent changes.
Launch the App Store and try updating your apps.
If you still see that dialog when updating, contact the Significator for iTunes developer here > http://www.ilijatovilo.ch/support
There's an email address available there.
- Temporarily disable anti virus software if installed.
- Apps such as Little Snitch, Net Nanny, and Hands Off can prevent apps and updates from downloading.
- Third party download managers are not compatible with the App Store.