It seems that  sun-web.xml or sun-ejb-jar.xml  XML validation takes forever for
me on my vpn system at home: the locally registered dtds or schemas do not seem
to be used. They are registered in the xml catalog.
Open these files in xml editor (popup menu edit). Make sure the AS 8.1 is
registered to get the DTDs. This was not happening before, I think, so it's a
regression imo, unless the plugin has to do somethinfI do not know.

Here is the dump thread when it takes a long time before validation ends:

"OpenIDE-request-processor-0" daemon prio=2 tid=0x0c38a498 nid=0xfe0 runnable [e
76f000..e76fd8c]
        at java.net.Inet4AddressImpl.lookupAllHostAddr(Native Method)
        at java.net.InetAddress$1.lookupAllHostAddr(InetAddress.java:770)
        at java.net.InetAddress.getAddressFromNameService(InetAddress.java:1059)

        at java.net.InetAddress.getAllByName0(InetAddress.java:1009)
        at java.net.InetAddress.getAllByName0(InetAddress.java:981)
        at java.net.InetAddress.getAllByName(InetAddress.java:975)
        at java.net.InetAddress.getByName(InetAddress.java:889)
        at java.net.InetSocketAddress.<init>(InetSocketAddress.java:114)
        at sun.net.NetworkClient.doConnect(NetworkClient.java:139)
        at sun.net.www.http.HttpClient.openServer(HttpClient.java:402)
        at sun.net.www.http.HttpClient$3.run(HttpClient.java:451)
        at java.security.AccessController.doPrivileged(Native Method)
        at sun.net.www.http.HttpClient.privilegedOpenServer(HttpClient.java:448)

        - locked <0x14e2ba68> (a sun.net.www.http.HttpClient)
        at sun.net.www.http.HttpClient.openServer(HttpClient.java:608)
        - locked <0x14e2ba68> (a sun.net.www.http.HttpClient)
        at sun.net.www.http.HttpClient.<init>(HttpClient.java:306)
        at sun.net.www.http.HttpClient.<init>(HttpClient.java:267)
        at sun.net.www.http.HttpClient.New(HttpClient.java:339)
        at sun.net.www.http.HttpClient.New(HttpClient.java:320)
        at sun.net.www.http.HttpClient.New(HttpClient.java:315)
        at sun.net.www.protocol.http.HttpURLConnection.plainConnect(HttpURLConne
ction.java:521)
        at sun.net.www.protocol.http.HttpURLConnection.connect(HttpURLConnection
.java:498)
        at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLCon
nection.java:626)
        - locked <0x14e2b7e0> (a sun.net.www.protocol.http.HttpURLConnection)
        at sun.net.www.protocol.http.HttpURLConnection.getHeaderField(HttpURLCon
nection.java:1465)
        at java.net.URLConnection.getContentType(URLConnection.java:382)
        at org.apache.crimson.parser.Resolver.resolveEntity(Resolver.java:388)
        at org.apache.crimson.parser.ExternalEntity.getInputSource(ExternalEntit
y.java:89)
        at org.apache.crimson.parser.Parser2.pushReader(Parser2.java:3327)
        at org.apache.crimson.parser.Parser2.externalParameterEntity(Parser2.jav
a:3062)
        at org.apache.crimson.parser.Parser2.maybeDoctypeDecl(Parser2.java:1347)

        at org.apache.crimson.parser.Parser2.parseInternal(Parser2.java:656)
        at org.apache.crimson.parser.Parser2.parse(Parser2.java:337)
        at org.apache.crimson.parser.XMLReaderImpl.parse(XMLReaderImpl.java:448)

        at org.netbeans.spi.xml.cookies.SharedXMLSupport.getNamespaces(SharedXML
Support.java:473)
        at org.netbeans.spi.xml.cookies.SharedXMLSupport.getSchemaLocations(Shar
edXMLSupport.java:449)
        at org.netbeans.spi.xml.cookies.SharedXMLSupport.parse(SharedXMLSupport.
java:170)
        at org.netbeans.spi.xml.cookies.SharedXMLSupport.validateXML(SharedXMLSu
pport.java:128)
        at org.netbeans.spi.xml.cookies.ValidateXMLSupport.validateXML(ValidateX
MLSupport.java:50)
        at org.netbeans.modules.xml.tools.actions.ValidateAction$RunAction.run(V
alidateAction.java:96)
        at org.openide.util.Task.run(Task.java:189)
        at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:330)

        at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java
:721)