Help understand the nature of the appearance of this error:

help understand the nature of the appearance of this error:

2010.01.25 15:36:09 ConnectionHandler:
java.io.IOException: Unknown error. Error code : -3 and message : invalid block type
at org.apache.mina.filter.support.Zlib.inflate(Zlib.java:139)
at org.apache.mina.filter.CompressionFilter.messageReceived(CompressionFilter.java :159)
at org.apache.mina.common.support.AbstractIoFilterChain.callNextMessageReceived(Ab stractIoFilterChain.java:299)
at org.apache.mina.common.support.AbstractIoFilterChain.access$1100(AbstractIoFilt erChain.java:53)
at org.apache.mina.common.support.AbstractIoFilterChain$EntryImpl$1.messageReceive d(AbstractIoFilterChain.java:648)
at org.apache.mina.filter.support.SSLHandler.flushScheduledEvents(SSLHandler.java: 275)
at org.apache.mina.filter.SSLFilter.messageReceived(SSLFilter.java:427)
at org.apache.mina.common.support.AbstractIoFilterChain.callNextMessageReceived(Ab stractIoFilterChain.java:299)
at org.apache.mina.common.support.AbstractIoFilterChain.access$1100(AbstractIoFilt erChain.java:53)
at org.apache.mina.common.support.AbstractIoFilterChain$EntryImpl$1.messageReceive d(AbstractIoFilterChain.java:648)
at org.apache.mina.common.support.AbstractIoFilterChain$HeadFilter.messageReceived (AbstractIoFilterChain.java:499)
at org.apache.mina.common.support.AbstractIoFilterChain.callNextMessageReceived(Ab stractIoFilterChain.java:299)
at org.apache.mina.common.support.AbstractIoFilterChain.fireMessageReceived(Abstra ctIoFilterChain.java:293)
at org.apache.mina.transport.socket.nio.SocketIoProcessor.read(SocketIoProcessor.j ava:228)
at org.apache.mina.transport.socket.nio.SocketIoProcessor.process(SocketIoProcesso r.java:198)
at org.apache.mina.transport.socket.nio.SocketIoProcessor.access$400(SocketIoProce ssor.java:45)
at org.apache.mina.transport.socket.nio.SocketIoProcessor$Worker.run(SocketIoProce ssor.java:485)
at org.apache.mina.util.NamePreservingRunnable.run(NamePreservingRunnable.java:51)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)