StringIndexOutOfBoundsException/DocletAbortException while running JavaDoc

While running JavaDoc (from Java 6) on some files, I see this exception:

java.lang.StringIndexOutOfBoundsException: String index out of range: -1

resulting in a DocletAbortException. I am unable to figure out what might be causing it (or even which of my files is triggering it). Here's the complete stack trace:

[javadoc] java.lang.StringIndexOutOfBoundsException: String index out of range: -1

[javadoc] at java.lang.String.substring(String.java:1932)

[javadoc] at com.sun.tools.doclets.internal.toolkit.util.VisibleMemberMap.getMemberKey(VisibleMemberMap.java:493)

[javadoc] at com.sun.tools.doclets.internal.toolkit.util.VisibleMemberMap.fillMemberLevelMap(VisibleMemberMap.java:178)

[javadoc] at com.sun.tools.doclets.internal.toolkit.util.VisibleMemberMap.access$700(VisibleMemberMap.java:28)

[javadoc] at com.sun.tools.doclets.internal.toolkit.util.VisibleMemberMap$ClassMembers.addMembers(VisibleMemberMap.java:326)

[javadoc] at com.sun.tools.doclets.internal.toolkit.util.VisibleMemberMap$ClassMembers.mapClass(VisibleMemberMap.java:285)

[javadoc] at com.sun.tools.doclets.internal.toolkit.util.VisibleMemberMap$ClassMembers.mapClass(VisibleMemberMap.java:297)

[javadoc] at com.sun.tools.doclets.internal.toolkit.util.VisibleMemberMap$ClassMembers.build(VisibleMemberMap.java:280)

[javadoc] at com.sun.tools.doclets.internal.toolkit.util.VisibleMemberMap$ClassMembers.access$100(VisibleMemberMap.java:230)

[javadoc] at com.sun.tools.doclets.internal.toolkit.util.VisibleMemberMap.<init>(VisibleMemberMap.java:93)

[javadoc] at com.sun.tools.doclets.internal.toolkit.builders.MemberSummaryBuilder.init(MemberSummaryBuilder.java:88)

[javadoc] at com.sun.tools.doclets.internal.toolkit.builders.MemberSummaryBuilder.getInstance(MemberSummaryBuilder.java:64)

[javadoc] at com.sun.tools.doclets.internal.toolkit.builders.BuilderFactory.getMemberSummaryBuilder(BuilderFactory.java:191)

[javadoc] at com.sun.tools.doclets.formats.html.ClassWriterImpl.navSummaryLinks(ClassWriterImpl.java:474)

[javadoc] at com.sun.tools.doclets.formats.html.ClassWriterImpl.printSummaryDetailLinks(ClassWriterImpl.java:456)

[javadoc] at com.sun.tools.doclets.formats.html.HtmlDocletWriter.navLinks(HtmlDocletWriter.java:462)

[javadoc] at com.sun.tools.doclets.formats.html.ClassWriterImpl.writeHeader(ClassWriterImpl.java:125)

[javadoc] at com.sun.tools.doclets.internal.toolkit.builders.ClassBuilder.buildClassHeader(ClassBuilder.java:164)

[javadoc] at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

[javadoc] at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)

[javadoc] at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)

[javadoc] at java.lang.reflect.Method.invoke(Method.java:597)

[javadoc] at com.sun.tools.doclets.internal.toolkit.builders.ClassBuilder.invokeMethod(ClassBuilder.java:101)

[javadoc] at com.sun.tools.doclets.internal.toolkit.builders.AbstractBuilder.build(AbstractBuilder.java:90)

[javadoc] at com.sun.tools.doclets.internal.toolkit.builders.ClassBuilder.buildClassDoc(ClassBuilder.java:124)

[javadoc] at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

[javadoc] at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)

[javadoc] at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)

[javadoc] at java.lang.reflect.Method.invoke(Method.java:597)

[javadoc] at com.sun.tools.doclets.internal.toolkit.builders.ClassBuilder.invokeMethod(ClassBuilder.java:101)

[javadoc] at com.sun.tools.doclets.internal.toolkit.builders.AbstractBuilder.build(AbstractBuilder.java:90)

[javadoc] at com.sun.tools.doclets.internal.toolkit.builders.ClassBuilder.build(ClassBuilder.java:108)

[javadoc] at com.sun.tools.doclets.formats.html.HtmlDoclet.generateClassFiles(HtmlDoclet.java:155)

[javadoc] at com.sun.tools.doclets.internal.toolkit.AbstractDoclet.generateClassFiles(AbstractDoclet.java:164)

[javadoc] at com.sun.tools.doclets.internal.toolkit.AbstractDoclet.startGeneration(AbstractDoclet.java:106)

[javadoc] at com.sun.tools.doclets.internal.toolkit.AbstractDoclet.start(AbstractDoclet.java:64)

[javadoc] at com.sun.tools.doclets.formats.html.HtmlDoclet.start(HtmlDoclet.java:42)

[javadoc] at com.sun.tools.doclets.standard.Standard.start(Standard.java:23)

[javadoc] at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

[javadoc] at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)

[javadoc] at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)

[javadoc] at java.lang.reflect.Method.invoke(Method.java:597)

[javadoc] at com.sun.tools.javadoc.DocletInvoker.invoke(DocletInvoker.java:215)

[javadoc] at com.sun.tools.javadoc.DocletInvoker.start(DocletInvoker.java:91)

[javadoc] at com.sun.tools.javadoc.Start.parseAndExecute(Start.java:340)

[javadoc] at com.sun.tools.javadoc.Start.begin(Start.java:128)

[javadoc] at com.sun.tools.javadoc.Main.execute(Main.java:41)

[javadoc] at com.sun.tools.javadoc.Main.main(Main.java:31)

[javadoc] com.sun.tools.doclets.internal.toolkit.util.DocletAbortException

[javadoc] at com.sun.tools.doclets.formats.html.ClassWriterImpl.printSummaryDetailLinks(ClassWriterImpl.java:467)