I use Intellij IDEA 13 on Ubuntu 13.10 (in Virtualbox) and maven for a project. Everything worked fine up until recently, when IDEA suddenly stopped giving suggestions for groupId, artifactId etc. for dependencies. I didn't do any changes to setting in IDEA or anywhere else. The only change I can remember doing around the same time was updating Virtualbox.
I noticed that in settings => maven => repositories the remote repository was set to http://repo.maven.org/maven2, and it gave an error. After fiddling a lot it suddenly changed back to http://repo1.maven.org/maven2 and doesn't give any error anymore.
But I still have the problem where IDEA refuses to give any suggestions when editing pom.xml files (except the modules in my project). If I run the build, it downloads all the depdencies and everything seems to work well.
Also, in "Artifactory or Nexus Service URLs" the http://oss.sonatype.org/service/local/ doesn't return any repositories. Don't know if it relevant.