Transfer Apps to iMac

I downloaded 3 apps in my iPad2. When sycing, the following error message appeared:
"Some of the purchased items on the iPdad could not be transferred to your iTunes library because you are not authorized for them on this computer."

This message appears even after the computer was authorized.

What now?

I'm not sure what it is you're trying to do? You can not transfer or sync apps designed for iOS to your Mac which uses an entirely different operating system. If you're trying to do something else, please explain.

Sounds like somebody is using two different iTunes accounts ...