"HTTP Server Unknown HTTP Response Code (302):http://devstudio.jboss.com/updates/5.0/central/core/content.xml" when updating JBDS plugins behind a proxy

Issue

While trying to install the SOA and Business Rule Tolling, I am encountering a HTTP 302, error code. All the proxy settings are correct an in place, and I have been able to install other plugins from other update sites.

org.eclipse.equinox.p2.core.ProvisionException: HTTP Server Unknown HTTP Response Code (302):http://devstudio.jboss.com/updates/5.0/central/core/content.xml
    at org.eclipse.equinox.internal.p2.repository.CacheManager.createCache(CacheManager.java:189)
    at org.eclipse.equinox.internal.p2.metadata.repository.SimpleMetadataRepositoryFactory.getLocalFile(SimpleMetadataRepositoryFactory.java:66)
    at org.eclipse.equinox.internal.p2.metadata.repository.SimpleMetadataRepositoryFactory.load(SimpleMetadataRepositoryFactory.java:88)
    at org.eclipse.equinox.internal.p2.metadata.repository.MetadataRepositoryManager.factoryLoad(MetadataRepositoryManager.java:57)
    at org.eclipse.equinox.internal.p2.repository.helpers.AbstractRepositoryManager.loadRepository(AbstractRepositoryManager.java:749)
    at org.eclipse.equinox.internal.p2.repository.helpers.AbstractRepositoryManager.loadRepository(AbstractRepositoryManager.java:651)
    at org.eclipse.equinox.internal.p2.metadata.repository.MetadataRepositoryManager.loadRepository(MetadataRepositoryManager.java:96)
    at org.eclipse.equinox.internal.p2.metadata.repository.MetadataRepositoryManager.loadRepository(MetadataRepositoryManager.java:92)
    at org.eclipse.mylyn.internal.discovery.ui.PrepareInstallProfileJob_e_3_6.addRepositories(PrepareInstallProfileJob_e_3_6.java:377)
    at org.eclipse.mylyn.internal.discovery.ui.PrepareInstallProfileJob_e_3_6.computeInstallableUnits(PrepareInstallProfileJob_e_3_6.java:202)
    at org.eclipse.mylyn.internal.discovery.ui.PrepareInstallProfileJob_e_3_6.run(PrepareInstallProfileJob_e_3_6.java:90)
    at org.eclipse.jface.operation.ModalContext$ModalContextThread.run(ModalContext.java:121)
Caused by: org.eclipse.ecf.filetransfer.BrowseFileTransferException: General connection error with response code=302
    at org.eclipse.ecf.provider.filetransfer.browse.URLFileSystemBrowser.runRequest(URLFileSystemBrowser.java:131)
    at org.eclipse.ecf.provider.filetransfer.browse.AbstractFileSystemBrowser$DirectoryJob.run(AbstractFileSystemBrowser.java:69)
    at org.eclipse.core.internal.jobs.Worker.run(Worker.java:54)