Error in fetching cookbooks from chef server

I am trying to fetch cookboks from my opscode hosted chef account.some cookbooks seems to fetch fine. for example chef_handler,bluepill,build-essential however when i try to fetch apache2, mysql that are there on my hosted chef server,
This is what i am trying to do.
ChefApi api = getAPI();
Set<String> cookbooks = api.listCookbooks();
for(String cookBook : cookbooks) {
Set<String> versionsOfCookbook = api.getVersionsOfCookbook(cookBook);
for(String s : versionsOfCookbook)

{ CookbookVersion cookbook = api.getCookbook(cookBook, s); }

But this throws exception for apache2, please take a look

SEVERE: Error parsing input
java.lang.IllegalArgumentException: duplicate key: apache2
at com.google.common.base.Preconditions.checkArgument(Preconditions.java:119)
at com.google.common.collect.RegularImmutableMap.<init>(RegularImmutableMap.java:67)
at com.google.common.collect.ImmutableMap$Builder.fromEntryList(ImmutableMap.java:249)
at com.google.common.collect.ImmutableMap$Builder.build(ImmutableMap.java:235)
at org.jclouds.json.internal.NullFilteringTypeAdapterFactories$MapTypeAdapter.read(NullFilteringTypeAdapterFactories.java:313)
at org.jclouds.json.internal.NullFilteringTypeAdapterFactories$MapTypeAdapter.read(NullFilteringTypeAdapterFactories.java:278)
at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$1.read(ReflectiveTypeAdapterFactory.java:93)
at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$Adapter.read(ReflectiveTypeAdapterFactory.java:176)
at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$1.read(ReflectiveTypeAdapterFactory.java:93)
at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$Adapter.read(ReflectiveTypeAdapterFactory.java:176)
at com.google.gson.Gson.fromJson(Gson.java:755)
at com.google.gson.Gson.fromJson(Gson.java:721)
at com.google.gson.Gson.fromJson(Gson.java:670)
at org.jclouds.json.internal.GsonWrapper.fromJson(GsonWrapper.java:47)
at org.jclouds.http.functions.ParseJson.apply(ParseJson.java:86)
at org.jclouds.http.functions.ParseJson.apply(ParseJson.java:80)
at org.jclouds.http.functions.ParseJson.apply(ParseJson.java:66)
at org.jclouds.http.functions.ParseJson.apply(ParseJson.java:46)
at org.jclouds.rest.internal.InvokeHttpMethod$InvokeAndTransform.call(InvokeHttpMethod.java:167)
at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303)
at java.util.concurrent.FutureTask.run(FutureTask.java:138)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
at java.lang.Thread.run(Thread.java:662)
20:20:03,274 ERROR [DispatcherPortlet:560] Could not complete request
java.lang.IllegalArgumentException: duplicate key: apache2
at com.google.common.base.Preconditions.checkArgument(Preconditions.java:119)
at com.google.common.collect.RegularImmutableMap.<init>(RegularImmutableMap.java:67)
at com.google.common.collect.ImmutableMap$Builder.fromEntryList(ImmutableMap.java:249)
at com.google.common.collect.ImmutableMap$Builder.build(ImmutableMap.java:235)
at org.jclouds.json.internal.NullFilteringTypeAdapterFactories$MapTypeAdapter.read(NullFilteringTypeAdapterFactories.java:313)
at org.jclouds.json.internal.NullFilteringTypeAdapterFactories$MapTypeAdapter.read(NullFilteringTypeAdapterFactories.java:278)
at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$1.read(ReflectiveTypeAdapterFactory.java:93)
at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$Adapter.read(ReflectiveTypeAdapterFactory.java:176)
at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$1.read(ReflectiveTypeAdapterFactory.java:93)
at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$Adapter.read(ReflectiveTypeAdapterFactory.java:176)
at com.google.gson.Gson.fromJson(Gson.java:755)
at com.google.gson.Gson.fromJson(Gson.java:721)
at com.google.gson.Gson.fromJson(Gson.java:670)
at org.jclouds.json.internal.GsonWrapper.fromJson(GsonWrapper.java:47)
at org.jclouds.http.functions.ParseJson.apply(ParseJson.java:86)
at org.jclouds.http.functions.ParseJson.apply(ParseJson.java:80)
at org.jclouds.http.functions.ParseJson.apply(ParseJson.java:66)
at org.jclouds.http.functions.ParseJson.apply(ParseJson.java:46)
at org.jclouds.rest.internal.InvokeHttpMethod$InvokeAndTransform.call(InvokeHttpMethod.java:167)
at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303)
at java.util.concurrent.FutureTask.run(FutureTask.java:138)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
at java.lang.Thread.run(Thread.java:662)

Chef Verison is 1.6.0,
Thanks in advance
Jayant