When I try to upload my app to iTC, after validate my app, I begin to submit it .
But there is an Error that said "iTunes Store operation failed
Error Description not available"
When I upload with Application Loader 3.0, same error happened.
I had this error once, too. Then I realized the provisioning profile (Project Targets -> Code Signing) was set to 'Ad-Hoc' profile instead of 'Production' profile. Setting it back to 'Production' did the trick for me.