NetBeans 6.9.1 build and ant targets give erronuous error messages even though build succeeds

I have a NetBeans 6.9.1 project with libraries stored in the netbeans project directory option checked. I also have some ant build scripts mounted in my project.

Now when i run any ant target (including the simplest possible ones like clean), or when i build the project from the IDE, i get the following output at the end of the build process in the output window.

I don't know how to get rid of these errors. I have tried re-creating the project because i read online that netbeans 6.5.1. had a problem with corrupting the build-impl.xml file, but that didn't solve my problem. The important thing is that the build does succeed, but it would be really nice to not see these error at the end of the build and have to scroll up in the output window every time to make sure the build worked (or failed if i screwed up a file or something).

Thanks for the help in advance.

Output:

BUILD SUCCESSFUL (total time: 1 second)
Could not load class (org.apache.tools.ant.taskdefs.repository.MavenRepository) for type mavenrepository
Could not load a dependent class (jdepend/xmlui/JDepend) for type jdepend
Could not load class (org.apache.tools.ant.taskdefs.optional.ejb.Ejbc) for type ejbc
Could not load class (org.apache.tools.ant.taskdefs.optional.ejb.WLStop) for type wlstop
Could not load class (org.apache.tools.ant.taskdefs.optional.ejb.WLRun) for type wlrun
Could not load a dependent class (javax/media/jai/PlanarImage) for type image
Could not load class (org.apache.tools.ant.taskdefs.optional.ejb.DDCreator) for type ddcreator
Could not load class (org.apache.tools.ant.taskdefs.optional.starteam.StarTeamCheckin) for type stcheckin
Could not load class (org.apache.tools.ant.taskdefs.optional.starteam.StarTeamCheckout) for type stcheckout
Could not load class (org.apache.tools.ant.taskdefs.optional.starteam.StarTeamLabel) for type stlabel
Could not load class (org.apache.tools.ant.taskdefs.optional.starteam.StarTeamList) for type stlist
Could not load class (org.apache.tools.ant.taskdefs.optional.scm.AntStarTeamCheckOut) for type starteam
Could not load class (org.apache.tools.ant.taskdefs.repository.MavenRepository) for type mavenrepository
Could not load a dependent class (jdepend/xmlui/JDepend) fo开发者_JAVA技巧r type jdepend
Could not load class (org.apache.tools.ant.taskdefs.optional.ejb.Ejbc) for type ejbc
Could not load class (org.apache.tools.ant.taskdefs.optional.ejb.WLStop) for type wlstop
Could not load class (org.apache.tools.ant.taskdefs.optional.ejb.WLRun) for type wlrun
Could not load a dependent class (javax/media/jai/PlanarImage) for type image
Could not load class (org.apache.tools.ant.taskdefs.optional.ejb.DDCreator) for type ddcreator
Could not load class (org.apache.tools.ant.taskdefs.optional.starteam.StarTeamCheckin) for type stcheckin
Could not load class (org.apache.tools.ant.taskdefs.optional.starteam.StarTeamCheckout) for type stcheckout
Could not load class (org.apache.tools.ant.taskdefs.optional.starteam.StarTeamLabel) for type stlabel
Could not load class (org.apache.tools.ant.taskdefs.optional.starteam.StarTeamList) for type stlist
Could not load class (org.apache.tools.ant.taskdefs.optional.scm.AntStarTeamCheckOut) for type starteam

If deployed ignore these message or change ant output level to normal.

If not check output on GlassFish tab.