Error 492 is somewhat related to .android_secure directory. The application tries to download the packages and due to permission restrictions or to a bug it is not allowed to store them for temporary use. In this case, you will need to copy all the content from the SD Card (in case you have one) and then format the SD Card from the smartphone's menu or just connect it to a computer with a card reader.
Also, enter Recovery mode and select Wipe Cache and from the Advanced menu use Wipe Dalvik Cache.
Another solution is to enter the settings menu found on your phone's application list and then go to Applications > Manage applications. Locate Play Store and click on it then use Clear Cache. Try to download the applications again from Play Store when you are finished.