My Maven Dependencies are ClassNotFound Exception or NoClassDefFoundError - eclipse

Question

Here again (I had to rewrite it to make it more comprehensive i guess):
I got project X and project Y. They are independant from each other. While project X is working with all hibernate dependencies, I get ClassNotFound Exceptions and NoClassDefFoundErrors on project Y with the same dependencies. The errors occur, because the hibernate jars seem not to be deployed on project Y. I have to put them jar by jar in the WEB-INF/lib folder that they get deployed for runtime, while in project X they are already deployed via dependencies. The difference: Project Y has a parent project.
Here the pom.xml s:
Working Project X:
<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>org.hibernate.tutorials</groupId>
<artifactId>hibernate-tutorial</artifactId>
<packaging>jar</packaging>
<version>1.0.0-SNAPSHOT</version>
<name>First Hibernate Tutorial</name>
<dependencies>
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-core</artifactId>
<version>4.1.3.Final</version>
</dependency>
<dependency>
<groupId>org.apache.tomcat</groupId>
<artifactId>servlet-api</artifactId>
<version>6.0.35</version>
</dependency>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-simple</artifactId>
<version>1.6.4</version>
</dependency>
<dependency>
<groupId>javassist</groupId>
<artifactId>javassist</artifactId>
<version>3.12.1.GA</version>
</dependency>
<dependency>
<groupId>javax.transaction</groupId>
<artifactId>jta</artifactId>
<version>1.1</version>
</dependency>
<dependency>
<groupId>org.hsqldb</groupId>
<artifactId>hsqldb</artifactId>
<version>2.0.0</version>
</dependency>
</dependencies>
</project>
Project Y:
<?xml version="1.0"?>
<project xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd" xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<modelVersion>4.0.0</modelVersion>
<parent>
<artifactId>com-project</artifactId>
<groupId>com.project</groupId>
<version>1.0-SNAPSHOT</version>
</parent>
<groupId>com.project.core</groupId>
<artifactId>com-project-core</artifactId>
<version>1.0-SNAPSHOT</version>
<packaging>war</packaging>
<name>com-project-core Jersey Webapp</name>
<dependencies>
<dependency>
<groupId>com.project.facade</groupId>
<artifactId>com-project-facade</artifactId>
<version>1.0-SNAPSHOT</version>
</dependency>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.8.2</version>
<scope>test</scope>
</dependency>
<!-- Hibernate -->
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-core</artifactId>
<version>4.1.3.Final</version>
</dependency>
<dependency>
<groupId>org.apache.tomcat</groupId>
<artifactId>servlet-api</artifactId>
<version>6.0.35</version>
</dependency>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-simple</artifactId>
<version>1.6.4</version>
</dependency>
<dependency>
<groupId>javassist</groupId>
<artifactId>javassist</artifactId>
<version>3.12.1.GA</version>
</dependency>
</dependencies>
</project>
Project Y parent pom:
<?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.project</groupId>
<artifactId>com-project</artifactId>
<version>1.0-SNAPSHOT</version>
<packaging>pom</packaging>
<name>com-project</name>
<url>http://maven.apache.org</url>
<modules>
<module>com-project-core</module>
<module>com-project-client</module>
<module>com-project-facade</module>
</modules>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
</properties>
</project>
I already tried this attempt, but its all set.