When i try to debug my webapp it starts up the tomcat server and the application, but shuts down the debugger shortly before the app gets usable. I see the debugging toolbar for a second before it vanishes again, though the app keeps running.

Tomcat-log:

Listening for transport dt_socket at address: 11555
23.03.2010 01:24:35 org.apache.catalina.core.AprLifecycleListener init
INFO: The APR based Apache Tomcat Native library which allows optimal performance in production environments was not found on the java.library.path: .:/Library/Java/Extensions:/System/Library/Java/Extensions:/usr/lib/java
23.03.2010 01:24:35 org.apache.coyote.http11.Http11Protocol init
INFO: Initializing Coyote HTTP/1.1 on http-8084
23.03.2010 01:24:35 org.apache.catalina.startup.Catalina load
INFO: Initialization processed in 847 ms
23.03.2010 01:24:35 org.apache.catalina.core.StandardService start
INFO: Starting service Catalina
23.03.2010 01:24:35 org.apache.catalina.core.StandardEngine start
INFO: Starting Servlet Engine: Apache Tomcat/6.0.20
log4j:WARN No appenders could be found for logger (org.springframework.web.context.ContextLoader).
log4j:WARN Please initialize the log4j system properly.
23.03.2010 01:24:41 org.apache.coyote.http11.Http11Protocol start
INFO: Starting Coyote HTTP/1.1 on http-8084
23.03.2010 01:24:41 org.apache.jk.common.ChannelSocket init
INFO: JK: ajp13 listening on /0.0.0.0:8009
23.03.2010 01:24:41 org.apache.jk.server.JkMain start
INFO: Jk running ID=0 time=0/78  config=null
23.03.2010 01:24:41 org.apache.catalina.startup.Catalina start
INFO: Server startup in 5855 ms
23.03.2010 01:24:42 org.apache.catalina.startup.HostConfig checkResources
INFO: Undeploying context []
23.03.2010 01:24:45 org.apache.catalina.core.StandardContext start
INFO: Container org.apache.catalina.core.ContainerBase.[Catalina].[localhost].[/] has already been started

Debugging log:

Attached JPDA debugger to localhost:11555
Checking data source definitions for missing JDBC drivers...
Deploying JDBC driver to /Applications/NetBeans/apache-tomcat-6.0.20/lib/mysql-connector-java-5.1.6-bin.jar
Stopping Tomcat process...
Waiting for Tomcat...
Tomcat server stopped.
Starting Tomcat process...
Waiting for Tomcat...
Tomcat server started.
Undeploying ...
OK - Undeployed application at context path /
In-place deployment at /path/to/project/dir/build/web
deploy?config=file%3A%2Fvar%2Ffolders%2FZP%2FZPbqxGrbHFaUlXzAfgWV1%2B%2B%2B%2BTQ%2F-Tmp-%2Fcontext734173871283203218.xml&path=/
OK - Deployed application at context path /
start?path=/
Start is in progress...
OK - Started application at context path /
debug-display-browser:
Browsing: http://localhost:8084/
connect-client-debugger:
BUILD SUCCESSFUL (total time: 18 seconds)

System is Netbeans 6.8 on MacOS 10.6.2.

Thank you very much, guys!