I also have that hs_err log file. Here's an excerpt from one of our client side crashes:
j java.lang.ClassLoader$NativeLibrary.load(Ljava/lang/String

V+0
j java.lang.ClassLoader.loadLibrary0(Ljava/lang/Class;Ljava/io/File

Z+300
j java.lang.ClassLoader.loadLibrary(Ljava/lang/Class;Ljava/lang/String;Z)V+48
j java.lang.Runtime.load0(Ljava/lang/Class;Ljava/lang/String

V+57
j java.lang.System.load(Ljava/lang/String

V+7
j com.pheox.jcapi.g.g()V+170
j com.pheox.jcapi.JCAPIProvider.init()V+16
j com.pheox.jcapi.JCAPIProvider.<clinit>()V+0
v ~StubRoutines::call_stub
V [jvm.dll+0x845a9]
V [jvm.dll+0xd9317]
V [jvm.dll+0x8447a]
V [jvm.dll+0x76f5d]
V [jvm.dll+0x75e58]
V [jvm.dll+0x7ef8b]
j testjcapi.envirohandler.ClientEnvironmentHandler$AutoPrivKeyFinder.findAutoPrivKey(Lcom/sun/xml/wss/impl/callback/SignatureKeyCallback$AliasPrivKeyCertRequest

V+4
j testjcapi.envirohandler.ClientEnvironmentHandler.handle([Ljavax/security/auth/callback/Callback

V+176
j com.sun.xml.wss.impl.misc.DefaultSecurityEnvironmentImpl.getAliasPrivKeyCertRequest(Ljava/lang/String

Lcom/sun/xml/wss/impl/callback/SignatureKeyCallback$AliasPrivKeyCertRequest;+34
j com.sun.xml.wss.impl.filter.SignatureFilter.process(Lcom/sun/xml/wss/impl/FilterProcessingContext

V+349
j com.sun.xml.wss.impl.HarnessUtil.processWSSPolicy(Lcom/sun/xml/wss/impl/FilterProcessingContext

V+16
j com.sun.xml.wss.impl.HarnessUtil.processDeep(Lcom/sun/xml/wss/impl/FilterProcessingContext

V+11
j com.sun.xml.wss.impl.SecurityAnnotator.processMessagePolicy(Lcom/sun/xml/wss/impl/FilterProcessingContext

V+70
j com.sun.xml.wss.impl.SecurityAnnotator.secureMessage(Lcom/sun/xml/wss/ProcessingContext

V+257
j com.sun.xml.xwss.XWSSClientPipe.secureRequest(Lcom/sun/xml/ws/api/message/Packet

Lcom/sun/xml/ws/api/message/Packet;+233
j com.sun.xml.xwss.XWSSClientPipe.process(Lcom/sun/xml/ws/api/message/Packet

Lcom/sun/xml/ws/api/message/Packet;+32
j com.sun.xml.ws.api.pipe.helper.PipeAdapter.processRequest(Lcom/sun/xml/ws/api/message/Packet

Lcom/sun/xml/ws/api/pipe/NextAction;+6
j com.sun.xml.ws.api.pipe.Fiber.__doRun(Lcom/sun/xml/ws/api/pipe/Tube

Lcom/sun/xml/ws/api/pipe/Tube;+206
j com.sun.xml.ws.api.pipe.Fiber._doRun(Lcom/sun/xml/ws/api/pipe/Tube

Lcom/sun/xml/ws/api/pipe/Tube;+31
j com.sun.xml.ws.api.pipe.Fiber.doRun(Lcom/sun/xml/ws/api/pipe/Tube

Lcom/sun/xml/ws/api/pipe/Tube;+84
j com.sun.xml.ws.api.pipe.Fiber.runSync(Lcom/sun/xml/ws/api/pipe/Tube;Lcom/sun/xml/ws/api/message/Packet

Lcom/sun/xml/ws/api/message/Packet;+48
j com.sun.xml.ws.client.Stub.process(Lcom/sun/xml/ws/api/message/Packet;Lcom/sun/xml/ws/client/RequestContext;Lcom/sun/xml/ws/client/ResponseContextReceiver

Lcom/sun/xml/ws/api/message/Packet;+140
j com.sun.xml.ws.client.sei.SEIStub.doProcess(Lcom/sun/xml/ws/api/message/Packet;Lcom/sun/xml/ws/client/RequestContext;Lcom/sun/xml/ws/client/ResponseContextReceiver

Lcom/sun/xml/ws/api/message/Packet;+4
j com.sun.xml.ws.client.sei.SyncMethodHandler.invoke(Ljava/lang/Object;[Ljava/lang/Object;Lcom/sun/xml/ws/client/RequestContext;Lcom/sun/xml/ws/client/ResponseContextReceiver

Ljava/lang/Object;+64
j com.sun.xml.ws.client.sei.SyncMethodHandler.invoke(Ljava/lang/Object;[Ljava/lang/Object

Ljava/lang/Object;+14
j com.sun.xml.ws.client.sei.SEIStub.invoke(Ljava/lang/Object;Ljava/lang/reflect/Method;[Ljava/lang/Object

Ljava/lang/Object;+24
j $Proxy28.helloWorld()Ljava/lang/String;+9
j testjcapi.client.TutorialClient.main([Ljava/lang/String

V+126