"mvn test" only keeps the last test in TestSuite.txt

[hbf]

Dear list,

I am using TestNG 5.8 with the maven-surefire-plugin 2.5 and do a "mvn
test". Two tests are failing, as indicated by the console output:

Tests run: 20, Failures: 2, Errors: 0, Skipped: 1
[INFO]
------------------------------------------------------------------------
[ERROR] BUILD FAILURE
[INFO]
------------------------------------------------------------------------
[INFO] There are test failures.
Please refer to /Users/hbf/Documents/workspace/is/is-platform/is-
service/target/surefire-reports for the individual test results.

However, target/surefire-reports/TestSuite.txt only contains
information about the (successful) TestNG tests in the last processed
java class, for example:

-------------------------------------------------------------------------------
Test set: TestSuite

-------------------------------------------------------------------------------
Tests run: 4, Failures: 0, Errors: 0, Skipped: 0, Time elapsed:
2.584 sec

(While Maven is processing "mvn test", I see that TestSuite.txt is
constantly being overwritten, it's 0kB, then 4kB, then 0kB again,
etc.)

Has anybody experienced a similar problem or an idea where the problem
might lie?

Many thanks for any pointers,
Kaspar

P.S. mvn help:effective-pom only contains version 5.8 of TestNG and

<reporting>
<outputDirectory>/Users/hbf/Documents/workspace/is/is-platform/is-
service/target/site</outputDirectory>
</reporting>
...
<plugin>
<artifactId>maven-surefire-plugin</artifactId>
<version>2.5</version>
<configuration>
<forkMode>always</forkMode>
<argLine>-javaagent:${settings.localRepository}/salve/salve-
agent/2.0-beta1/salve-agent-2.0-beta1.jar</argLine>
<useSystemClassloader>false</useSystemClassloader>
</configuration>
</plugin>

but there is also a

</pluginManagement>
...
<plugin>
<artifactId>maven-surefire-plugin</artifactId>
<version>2.4.3</version>
</plugin>
...
</plugins>
</pluginManagement>

Could this be the cause of the problem?