Help with Error in Openfire

Can someone tell me what may be going on here? I notice spikes to the server and then disconnects. The server itself doesn't go down, but people are kicked off and it reconnects.

2013.04.24 14:52:43 org.jivesoftware.openfire.nio.ConnectionHandler - Closing session due to exception: (SOCKET, R: /172.17.64.76:60122, L: /10.136.234.109:5222, S: 0.0.0.0/0.0.0.0:5222)

org.apache.mina.filter.codec.ProtocolDecoderException: org.jivesoftware.openfire.nio.XMLNotWellFormedException: Character is invalid in: (Hexdump: 17 03 01 00 5D 35 E3 06 1E 84 F2 C0 8C EC A7 05 36 0F 68 0A 8B 0E 56 17 3A 7E AB 84 5D E3 34 3D 08 01 0A 2C 23 C6 2B 41 B1 FC 14 3F 25 B6 40 89 CF D5 84 E5 DD 7A 9B 75 0B 29 25 86 B0 72 48 24 54 4B 9E EA 8E DA A1 73 50 D0 05 0D 31 6E B1 A6 10 D9 E2 26 60 EA 0D D0 A6 03 B8 4C BF 92 AA 5A 30 1E)

at org.apache.mina.filter.codec.ProtocolCodecFilter.messageReceived(ProtocolCodecF ilter.java:170)

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.executor.ExecutorFilter.processEvent(ExecutorFilter.java :239)

at org.apache.mina.filter.executor.ExecutorFilter$ProcessEventsRunnable.run(Execut orFilter.java:283)

at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(Unknown Source)

at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)

at org.apache.mina.util.NamePreservingRunnable.run(NamePreservingRunnable.java:51)

at java.lang.Thread.run(Unknown Source)

Caused by: org.jivesoftware.openfire.nio.XMLNotWellFormedException: Character is invalid in:

at org.jivesoftware.openfire.nio.XMLLightweightParser.read(XMLLightweightParser.ja va:208)

at org.jivesoftware.openfire.nio.XMPPDecoder.doDecode(XMPPDecoder.java:41)

at org.apache.mina.filter.codec.CumulativeProtocolDecoder.decode(CumulativeProtoco lDecoder.java:133)

at org.apache.mina.filter.codec.ProtocolCodecFilter.messageReceived(ProtocolCodecF ilter.java:163)

... 9 more

2013.04.24 14:52:43 org.jivesoftware.openfire.nio.ConnectionHandler - Closing session due to exception: (SOCKET, R: /172.17.64.209:64869, L: /10.136.234.109:5222, S: 0.0.0.0/0.0.0.0:5222)

org.apache.mina.filter.codec.ProtocolDecoderException: org.jivesoftware.openfire.nio.XMLNotWellFormedException: Character is invalid in: (Hexdump: 17 03 01 00 5D C3 89 E4 A9 83 2D D0 68 64 29 4D 42 6A 48 27 F0 F9 4F EC FA 31 A7 FD AE 81 4D 61 EC 6D 71 87 35 0B 65 9E 68 51 44 4E F2 2D 16 4E 72 08 D4 C7 66 3B D3 7D D7 D2 18 C9 90 BB 26 30 CB 75 9C C7 0D E6 11 81 B0 87 88 B8 85 AE 38 15 FC 47 2E B6 CD D2 27 4F 66 06 88 42 2A FE CB E2 75 FA)