Just to summarize and extend on Aron and Richards posts below these would probably be the steps to try:

1) Try running "mvn clean install -DskipTests" from a directory containing the CollectionSpace services source code and see if the problem is still occurring.
2) If the problem is still present, go to: http://source.collectionspace.org:8081/artifactory/repo/org/nuxeo/ in a browser from the same location from which you have tried running the install. If you have problems accessing this address, it could be a firewall issue on your side.

Oh, I should also mention that I have installed CollectionSpace on Debian 5 several times, so I dont believe that the Linux flavour/version should be the issue here.

Following up on Richard Millet's recent posts, have just verified that port 8081 (used by the project Maven repository) is open, and that the relevant artifacts mentioned or implied in your initial problem report (nuxeo-core-api-1.6.2.pom and nuxeo-core-api-1.6.2.jar) are currently downloadable.

Project team members and implementers have been able to perform installations which depend on, and download, those artifacts from a wide variety of networks in various locations throughout the US, Canada, and Europe.

Thank you for your interest in CollectionSpace, and you have our sincere apologies for the delay in responding. If you're still encountering this particular issue, or any other difficulties getting a CollectionSpace system installed and running, please feel free to post here in the Forums or on the CollectionSpace Talk list (see the list of mailing lists below the lists of Forums), and we'll endeavor to respond promptly.

We have a cached reference to some of the Nuxeo libs for our development builds. See the following URL:

http://source.collectionspace.org:8081/artifactory/repo/org/nuxeo/

The corresponding Maven repository declaration is:

<repository>
<id>collectionspace</id>
<name>collectionspace-releases</name>
<url>http://source.collectionspace.org:8081/artifactory/nuxeo-public</url>
</repository>