Spring snapshots

Hi,

I am trying to understand mavens downloading of snapshots (maven 3.0.4,
vanilla install)

I use only spring RELEASE (3.1.4.RELEASE) builds in my pom and I have no
repository definitions in the pom.
When I display the dependency tree with mvn dependency:tree I also see that
my project has no dependencies on snapshots.

Nevertheless, every day, maven pulls in loads of snapshots from the spring
snapshot repository.

How can I avoid downloading the snapshots?