I installed Oracle SOA Suite 11g.
I start the NodeManager successfully.
I start the AdminServer successfully. When I go to start the soa serve (soa_server1) I get this output:

NMProcess: <Mar 15, 2010 3:33:30 PM> <WARNING> <Exception while starting server 'soa_server1'>  
NMProcess: java.io.IOException: Server failed to start up. See server output log for more details.  
NMProcess:      at weblogic.nodemanager.server.ServerManager.start(ServerManager.java:331)    
NMProcess:      at weblogic.nodemanager.server.Handler.handleStart(Handler.java:541)  
NMProcess:      at weblogic.nodemanager.server.Handler.handleCommand(Handler.java:116)  
NMProcess:      at weblogic.nodemanager.server.Handler.run(Handler.java:70)  
NMProcess:      at java.lang.Thread.run(Thread.java:619)  
NMProcess:
NMProcess: Mar 15, 2010 3:33:30 PM weblogic.nodemanager.server.Handler handleStart  
NMProcess: WARNING: Exception while starting server 'soa_server1'  
NMProcess: java.io.IOException: Server failed to start up. See server output log for more details.  
NMProcess:      at weblogic.nodemanager.server.ServerManager.start(ServerManager.java:331)  
NMProcess:      at weblogic.nodemanager.server.Handler.handleStart(Handler.java:541)  
NMProcess:      at weblogic.nodemanager.server.Handler.handleCommand(Handler.java:116)  
NMProcess:      at weblogic.nodemanager.server.Handler.run(Handler.java:70)   
NMProcess:      at java.lang.Thread.run(Thread.java:619)  
Error Starting server soa_server1: weblogic.nodemanager.NMException: Exception while starting server 'soa_server1'  

In the log file I've got this:

Enter username to boot WebLogic server:Enter password to boot WebLogic server:

There are 1 nested errors:

weblogic.management.ManagementException: Booting as admin server, but servername, soa_server1, does not match the admin server name, AdminServer
    at weblogic.management.provider.internal.RuntimeAccessService.start(RuntimeAccessService.java:67)
    at weblogic.t3.srvr.ServerServicesManager.startService(ServerServicesManager.java:461)
    at weblogic.t3.srvr.ServerServicesManager.startInStandbyState(ServerServicesManager.java:166)
    at weblogic.t3.srvr.T3Srvr.initializeStandby(T3Srvr.java:749)
    at weblogic.t3.srvr.T3Srvr.startup(T3Srvr.java:488)
    at weblogic.t3.srvr.T3Srvr.run(T3Srvr.java:446)
    at weblogic.Server.main(Server.java:67)

>
<Mar 15, 2010 3:33:30 PM ART> <Notice> <WebLogicServer> <BEA-000365> <Server state changed to FAILED>
<Mar 15, 2010 3:33:30 PM ART> <Error> <WebLogicServer> <BEA-000383> <A critical service failed. The server will shut itself down>
<Mar 15, 2010 3:33:30 PM ART> <Notice> <WebLogicServer> <BEA-000365> <Server state changed to FORCE_SHUTTING_DOWN>
<Mar 15, 2010 3:33:30 PM> <FINEST> <NodeManager> <Waiting for the process to die: 31144>
<Mar 15, 2010 3:33:30 PM> <INFO> <NodeManager> <Server failed during startup so will not be restarted>
<Mar 15, 2010 3:33:30 PM> <FINEST> <NodeManager> <runMonitor returned, setting finished=true and notifying waiters>

Do you have any clue of what is happening? If you need more info, just ask for it.

thanks in advance