error when trying to run data management tool when behind a proxied firewall

Using -Dhttp.proxyHost=proxyhost.com, -Dhttp.proxyPort=80 -Dproxy.User=myuserid -Dhttp.proxyPassword=mypassword doesn't work
Setting -Djava.net.useSystemProxies=true doesn't work
Setting -Dhttp.auth.ntlm.domain=mydomain doesn't work
Nor does it pick up the proxy settings in my settings.xml file.

0 [main] INFO org.apache.maven.continuum.management.DataManagementCli - Processing Continuum database...
Exception in thread "main" org.apache.maven.artifact.resolver.MultipleArtifactsNotFoundException: Missing:
----------
1) org.apache.maven.continuum:data-management-jdo:jar:1.1-beta-3

Try downloading the file manually from the project website.

Then, install it using the command:
mvn install:install-file -DgroupId=org.apache.maven.continuum -DartifactId=data-management-jdo \
-Dversion=1.1-beta-3 -Dpackaging=jar -Dfile=/path/to/file

Path to dependency:
1) dummy:dummy:pom:1.0
2) org.apache.maven.continuum:data-management-jdo:jar:1.1-beta-3

----------
1 required artifact is missing.

for artifact:
dummy:dummy:pom:1.0

from the specified remote repositories:
central (http://repo1.maven.org/maven2)

at org.apache.maven.artifact.resolver.DefaultArtifactResolver.resolveTransitively(DefaultArtifactResolver.java:305)
at org.apache.maven.artifact.resolver.DefaultArtifactResolver.resolveTransitively(DefaultArtifactResolver.java:272)
at org.apache.maven.artifact.resolver.DefaultArtifactResolver.resolveTransitively(DefaultArtifactResolver.java:243)
at org.apache.maven.continuum.management.DataManagementCli.downloadArtifact(DataManagementCli.java:292)
at org.apache.maven.continuum.management.DataManagementCli.processDatabase(DataManagementCli.java:173)
at org.apache.maven.continuum.management.DataManagementCli.main(DataManagementCli.java:146)