ant4eclipse:getUsedProjects crashes in org.ant4eclipse.ant.jdt.type.JdtClassPathContainerType.doValidate

My ant script works fine with ant4eclipse 0.5.0.rc1.
Now I'm moving forward to use ant4eclipse 1.0.0.M1.
I updated my script for 1.0.0.M1:
ant taskdef
ant4eclipse:installedJREs & ant4eclipse:jdtClassPathLibrary instead of <path id="..." />
ant4eclipse:getUsedProjects instead of getReferencedProjects (workspaceDirectory instead workspace)

Now in 1.0.0.M1 ant4eclipse:getUsedProjects fails in class: org.ant4eclipse.ant.jdt.type.JdtClassPathContainerType.doValidate(JdtClassPathContainerType.java:101)

I also tried to use org.ant4eclipse_1745.zip for Hudson build 26.
Stack trace from org.ant4eclipse_1745.zip:
java.lang.NullPointerException
at org.ant4eclipse.ant.jdt.type.JdtClassPathContainerType.doValidate(JdtClassPathContainerType.java:102)
at org.ant4eclipse.ant.core.AbstractAnt4EclipseDataType.validate(AbstractAnt4EclipseDataType.java:76)
at org.ant4eclipse.ant.core.AbstractAnt4EclipseDataType.validateAll(AbstractAnt4EclipseDataType.java:101)
at org.ant4eclipse.ant.core.AbstractAnt4EclipseTask.execute(AbstractAnt4EclipseTask.java:63)
at org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:288)
at sun.reflect.GeneratedMethodAccessor4.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.apache.tools.ant.dispatch.DispatchUtils.execute(DispatchUtils.java:106)
at org.apache.tools.ant.Task.perform(Task.java:348)
at org.apache.tools.ant.Target.execute(Target.java:357)
at org.apache.tools.ant.Target.performTasks(Target.java:385)
at org.apache.tools.ant.Project.executeSortedTargets(Project.java:1337)
at org.apache.tools.ant.Project.executeTarget(Project.java:1306)
at org.apache.tools.ant.helper.DefaultExecutor.executeTargets(DefaultExecutor.java:41)
at org.apache.tools.ant.Project.executeTargets(Project.java:1189)
at org.apache.tools.ant.Main.runBuild(Main.java:758)
at org.apache.tools.ant.Main.startAnt(Main.java:217)
at org.apache.tools.ant.launch.Launcher.run(Launcher.java:257)
at org.apache.tools.ant.launch.Launcher.main(Launcher.java:104)