If you try to use Seam Remoting running it with SUN's JVM (1.5.08 and 1.5.09) you get an IllegalAccessError in the InterfaceGenerator class.

17:40:44,187 ERROR [[Seam Remoting]] Servlet.service() for servlet Seam Remoting threw exception
java.lang.IllegalAccessError: tried to access method java.lang.StringBuilder.append(Ljava/lang/StringBuilder;)Ljava/lang
/StringBuilder; from class org.jboss.seam.remoting.InterfaceGenerator
 at org.jboss.seam.remoting.InterfaceGenerator.appendClassSource(InterfaceGenerator.java:584)
 at org.jboss.seam.remoting.InterfaceGenerator.appendTypeSource(InterfaceGenerator.java:414)
 at org.jboss.seam.remoting.InterfaceGenerator.appendComponentSource(InterfaceGenerator.java:330)
 at org.jboss.seam.remoting.InterfaceGenerator.generateComponentInterface(InterfaceGenerator.java:131)
 at org.jboss.seam.remoting.InterfaceGenerator.handle(InterfaceGenerator.java:101)
 at org.jboss.seam.remoting.SeamRemotingServlet.doPost(SeamRemotingServlet.java:77)
 at org.jboss.seam.remoting.SeamRemotingServlet.doGet(SeamRemotingServlet.java:62)
 at javax.servlet.http.HttpServlet.service(HttpServlet.java:697)
 at javax.servlet.http.HttpServlet.service(HttpServlet.java:810)
 at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:252)
 at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
 at org.jboss.web.tomcat.filters.ReplyHeaderFilter.doFilter(ReplyHeaderFilter.java:96)
 at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202)
 at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
 at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:213)
 at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:178)
 at org.jboss.web.tomcat.security.SecurityAssociationValve.invoke(SecurityAssociationValve.java:175)
 at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:524)
 at org.jboss.web.tomcat.security.JaccContextValve.invoke(JaccContextValve.java:74)
 at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:126)
 at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:105)
 at org.jboss.web.tomcat.tc5.jca.CachedConnectionValve.invoke(CachedConnectionValve.java:156)
 at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:107)
 at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148)
 at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:869)
 at org.apache.coyote.http11.Http11BaseProtocol$Http11ConnectionHandler.processConnection(Http11BaseProtocol.java:664)
 at org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:527)
 at org.apache.tomcat.util.net.MasterSlaveWorkerThread.run(MasterSlaveWorkerThread.java:112)
 at java.lang.Thread.run(Thread.java:595)

Switching to IBM's JVM (1.5.0.3) and the problem does not happen.

Changing the lines (584~586) from (CVS-20061029):

typeSource.append(fields);
typeSource.append(accessors);
typeSource.append(mutators);

to:

typeSource.append(fields.toString());
typeSource.append(accessors.toString());
typeSource.append(mutators.toString());

and rebuilding SEAM solved the problem.

Not a bug directly related to SEAM but I guess most people running Windows use SUN's JVM.