Intellij Idea 12 Ultimate cannot correctly import pom for Scala project - scala

Question

I have a project I've been working with in Idea for weeks with no issues. I added a new maven dependency and it was not able to find the classes in it, even with maven re-import run, invalidating caches, etc. So, I started over by re-importing the pom - but now it cannot find ANY of the Scala symbols, even auto-imported Scala symbols. I have tried this multiple times with the same result. Here is the pom in question (with some details changed):
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.aa</groupId>
<artifactId>test-project</artifactId>
<version>1.0-SNAPSHOT</version>
<properties>
<!-- Explicitly declaring the source encoding eliminates the following message: -->
<!-- [WARNING] Using platform encoding (UTF-8 actually) to copy filtered
resources, i.e. build is platform dependent! -->
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<compiler.plugin.version>2.3.1</compiler.plugin.version>
<maven.compiler.target>1.8</maven.compiler.target>
<maven.compiler.source>1.8</maven.compiler.source>
</properties>
<dependencies>
<!-- Scala -->
<dependency>
<groupId>org.scala-lang</groupId>
<artifactId>scala-library</artifactId>
<version>2.10.1</version>
</dependency>
<dependency>
<groupId>org.scalatest</groupId>
<artifactId>scalatest_2.10.0</artifactId>
<version>2.0.M5</version>
</dependency>
<!-- Akka -->
<dependency>
<groupId>com.typesafe.akka</groupId>
<artifactId>akka-actor_2.10</artifactId>
<version>2.1.2</version>
</dependency>
<dependency>
<groupId>com.typesafe.akka</groupId>
<artifactId>akka-remote_2.10</artifactId>
<version>2.1.2</version>
</dependency>
<dependency>
<groupId>com.typesafe.akka</groupId>
<artifactId>akka-kernel_2.10</artifactId>
<version>2.1.2</version>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.scala-tools</groupId>
<artifactId>maven-scala-plugin</artifactId>
<executions>
<execution>
<id>compile</id>
<goals>
<goal>compile</goal>
</goals>
<phase>compile</phase>
</execution>
<execution>
<id>test-compile</id>
<goals>
<goal>testCompile</goal>
</goals>
<phase>test-compile</phase>
</execution>
<execution>
<phase>process-resources</phase>
<goals>
<goal>compile</goal>
</goals>
</execution>
</executions>
</plugin>
<plugin>
<groupId>org.scalastyle</groupId>
<artifactId>scalastyle-maven-plugin</artifactId>
<version>0.2.0</version>
<configuration>
<verbose>false</verbose>
<failOnViolation>true</failOnViolation>
<includeTestSourceDirectory>true</includeTestSourceDirectory>
<failOnWarning>false</failOnWarning>
<sourceDirectory>${basedir}/src/main/scala</sourceDirectory>
<testSourceDirectory>${basedir}/src/test/scala</testSourceDirectory>
<configLocation>${basedir}/src/main/resources/scalastyle_config.xml</configLocation>
<outputFile>${project.basedir}/scalastyle-output.xml</outputFile>
<outputEncoding>UTF-8</outputEncoding>
</configuration>
<executions>
<execution>
<goals>
<goal>check</goal>
</goals>
</execution>
</executions>
</plugin>
<plugin>
<artifactId>maven-compiler-plugin</artifactId>
<version>${compiler.plugin.version}</version>
<configuration>
<source>${maven.compiler.source}</source>
<target>${maven.compiler.target}</target>
</configuration>
</plugin>
</plugins>
</build>
</project>
I've been fighting with this for an hour now and am about at my wit's end. It builds fine from the command-line. But, again, nothing builds in Idea - it doesn't even see the symbols in scala.predef, etc.
Enabling the Scala facet for the module doesn't make any difference either.
I didn't find any reports of similar issues so perhaps I really am missing something.