Several users report that q4e 0.81 works with SIE 2.7.4 and 2.8.0. Installing the Scala plugin first has been recommended. Start by creating a Maven project, then add the Scala nature to it.
m2eclipse appears to require that the Scala IDE implement an m2eclipse specific extension point otherwise it processes Scala projects incorrectly. Contributions from the community to support this would be welcome, but until then m2eclipse is not recommended. Josh Suereth writes in this thread as at 2009-04-09
"The maven-eclipse-plugin is currently "broken" in the sense that it won't pay attention to the source directories configured by the maven-scala-plugin." He advises "Remember though, using mvn eclipse:eclipse does not give the "Scala IDE for Eclipse" any chance to fix/edit its configuration. Most eclipse plugins assume they have full control over their configuration and when doing things through eclipse APIs, they have a chance to respond and tweak the project settings appropriately. This means that any bugs you run into in eclispe should be reproduced without using mvn eclipse:eclipse. This is why you should prefer eclipse plugins, rather than maven plugins, to do integration between Scala + Maven + Eclipse."
Josh Sureth has a (on hold) Maven Scala integration project, [ESMi][], described as "The goal of ESMi would be to provide glue between the various means of creating a project: "Create Scala Project, then Enable maven dependency management, then fix build path", "Import Maven Project then add Scala nature then fix build path" or "Create Java Project, Add Scala nature, Enable Maven dependency management then fix build path" (my current choice)"