IRIResolverNormal needs thread safe CacheLRU

The following exception may occur when more than one thread requires access to the org.apache.jena.atlas.lib.cache.CacheLRU embedded in IRIResolverNormal:

Caused by: java.lang.NullPointerException
at java.util.LinkedHashMap.get(LinkedHashMap.java:339)
at org.apache.jena.atlas.lib.cache.CacheLRU.get(CacheLRU.java:53)
at org.apache.jena.riot.system.IRIResolver$IRIResolverNormal.resolveSilent(IRIResolver.java:427)
at org.apache.jena.riot.system.IRIResolver$IRIResolverNormal.<init>(IRIResolver.java:383)
at org.apache.jena.riot.system.IRIResolver.create(IRIResolver.java:210)
at org.apache.jena.riot.system.RiotLib.profile(RiotLib.java:141)
at org.apache.jena.riot.system.RiotLib.profile(RiotLib.java:130)
at org.apache.jena.riot.lang.LangRDFXML.<init>(LangRDFXML.java:104)
at org.apache.jena.riot.lang.LangRDFXML.create(LangRDFXML.java:74)
at org.apache.jena.riot.RiotReader.createParser(RiotReader.java:128)
at org.apache.jena.riot.RDFParserRegistry$ReaderRIOTFactoryImpl$1.read(RDFParserRegistry.java:141)
at org.apache.jena.riot.RDFDataMgr.process(RDFDataMgr.java:818)
at org.apache.jena.riot.RDFDataMgr.read(RDFDataMgr.java:258)
at org.apache.jena.riot.RDFDataMgr.read(RDFDataMgr.java:244)
at org.apache.jena.riot.adapters.RDFReaderRIOT.read(RDFReaderRIOT.java:69)
at com.ibm.team.jis.lqe.resource.RDFEntity.getModel(RDFEntity.java:361)
... 39 more

This may be related to the problem reported that is suppose to be fixed by the cloned issue. It looks to be the same stack trace. I've attached a test to reproduce. Works with Oracle Oracle JRE 1.6.0.27 but not IBM jre. Keep stopping and restarting the test until the NPE happens. NPE usually happens right off the start.