XCode 4.2 validating issues

Today I came across a weird behavior as I was trying to validate an app I had previously and successfully managed to archive.
The build and archiving phases went fine (no errors).
But as I tried to validate the new version of the app before publishing it to the app store, I was given the following error:

It came up XCode was compiling the app only for armv7 architectures.
I solved the issue by changing the "Architectures" voice under Projects Settings -> Setting -> Architectures. I've deleted the previous setting (it was ARCHS_STANDARD_32_BIT) and added two new lines:

armv7
armv6