Closed a jsp file and received concurrent mod exception... not much else was
going on.. I was running the application through the IDE at the time..

*********** Exception occurred ************ at 3:00 PM on May 26, 2006
java.util.ConcurrentModificationException
	at org.openide.util.WeakSet$WeakSetIterator.checkModcount(WeakSet.java:429)
	at org.openide.util.WeakSet$WeakSetIterator.hasNext(WeakSet.java:380)
	at java.util.Collections$UnmodifiableCollection$1.hasNext(Collections.java:1009)
[catch] at
org.netbeans.modules.j2ee.sun.ide.j2ee.LogViewerSupport.run(LogViewerSupport.java:111)

and the info from the log...

>System Info: 
  Product Version         = NetBeans 5.5 Beta (Build 200605090801)
  Operating System        = Linux version 2.6.10 running on i386
  Java; VM; Vendor; Home  = 1.5.0_06; Java HotSpot(TM) Client VM 1.5.0_06-b05;
Sun Microsystems Inc.; /opt/jdk1.5.0_06/jre
  System Locale; Encoding = en_US (nb); ISO-8859-1
  Home Dir.; Current Dir. = /home/duke; /home/duke/Desktop
  Installation; User Dir. =
/home/duke/netbeans-5.5beta/nb5.5:/home/duke/netbeans-5.5beta/ide7:/home/duke/netbeans-5.5beta/enterprise3:/home/duke/netbeans-5.5beta/harness:/home/duke/netbeans-5.5beta/soa1:/home/duke/netbeans-5.5beta/uml2:/home/duke/netbeans-5.5beta/xmltools1:/home/duke/netbeans-5.5beta/platform6;
/home/duke/.netbeans/5.5beta
  Boot & Ext. Classpath   =
/opt/jdk1.5.0_06/jre/lib/rt.jar:/opt/jdk1.5.0_06/jre/lib/i18n.jar:/opt/jdk1.5.0_06/jre/lib/sunrsasign.jar:/opt/jdk1.5.0_06/jre/lib/jsse.jar:/opt/jdk1.5.0_06/jre/lib/jce.jar:/opt/jdk1.5.0_06/jre/lib/charsets.jar:/opt/jdk1.5.0_06/jre/classes:/opt/jdk1.5.0_06/jre/lib/ext/sunjce_provider.jar:/opt/jdk1.5.0_06/jre/lib/ext/sunpkcs11.jar:/opt/jdk1.5.0_06/jre/lib/ext/dnsns.jar:/opt/jdk1.5.0_06/jre/lib/ext/localedata.jar
  Application Classpath   =
/home/duke/netbeans-5.5beta/platform6/lib/boot.jar:/home/duke/netbeans-5.5beta/platform6/lib/org-openide-modules.jar:/home/duke/netbeans-5.5beta/platform6/lib/org-openide-util.jar:/opt/jdk1.5.0_06/lib/dt.jar:/opt/jdk1.5.0_06/lib/tools.jar
  Startup Classpath       =
/home/duke/netbeans-5.5beta/platform6/core/core.jar:/home/duke/netbeans-5.5beta/platform6/core/org-openide-filesystems.jar:/home/duke/netbeans-5.5beta/nb5.5/core/org-netbeans-upgrader.jar:/home/duke/netbeans-5.5beta/nb5.5/core/locale/core_nb.jar:/home/duke/netbeans-5.5beta/ide7/core/org-netbeans-modules-utilities-cli.jar