StringIndexOutOfBoundsException - both cmd and ant error

Hi there, having the following pblm. Using pmd 1.0 (latest available version, archived named 1.0.1 something)

BUILD FAILED
java.lang.StringIndexOutOfBoundsException: String index out of range: -1
        at java.lang.String.substring(String.java:1938)
        at com.adobe.ac.pmd.nodes.impl.MetaDataNode.compute(MetaDataNode.java:54)
        at com.adobe.ac.pmd.nodes.impl.NodeFactory.createMetaData(NodeFactory.java:41)
        at com.adobe.ac.pmd.nodes.utils.MetaDataUtils.computeMetaDataList(MetaDataUtils.java:46)
        at com.adobe.ac.pmd.nodes.impl.FunctionNode.compute(FunctionNode.java:120)
        at com.adobe.ac.pmd.nodes.impl.ClassNode.detectFunction(ClassNode.java:306)
        at com.adobe.ac.pmd.nodes.impl.ClassNode.computeClassContent(ClassNode.java:262)
        at com.adobe.ac.pmd.nodes.impl.ClassNode.compute(ClassNode.java:103)
        at com.adobe.ac.pmd.nodes.impl.PackageNode.compute(PackageNode.java:73)
        at com.adobe.ac.pmd.nodes.impl.NodeFactory.createPackage(NodeFactory.java:46)
        at com.adobe.ac.pmd.files.FileSetUtils.computeAsts(FileSetUtils.java:101)
        at com.adobe.ac.pmd.FlexPmdViolations.computeAsts(FlexPmdViolations.java:118)
        at com.adobe.ac.pmd.FlexPmdViolations.computeViolations(FlexPmdViolations.java:96)
        at com.adobe.ac.pmd.engines.AbstractFlexPmdEngine.computeViolations(AbstractFlexPmdEngine.java:156)
        at com.adobe.ac.pmd.engines.AbstractFlexPmdEngine.executeReport(AbstractFlexPmdEngine.java:138)
        at com.adobe.ac.pmd.ant.FlexPmdAntTask.execute(FlexPmdAntTask.java:64)
        at org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:288)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
        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)

Total time: 0 seconds

could you advise what can be the problem?