Error connecting to RTC 3.0.1 via Eclipse Client

Our RTC 3.0.1 server is accessible without ssl (http on port 80).
Inside the LAN, access is ok for web client and Eclipse client.
Another access is configured outside the LAN, using a firewall and a reverse-proxy.
Actually, external users may connect with web client but can't with Eclipse client.
Here is the Eclipse log detail :

!ENTRY org.eclipse.ui 4 4 2011-07-11 15:07:53.597
!MESSAGE Plug-in 'com.ibm.team.interop.ide.ui' contributed an invalid Menu Extension (Path: 'jazz.manage' is invalid): com.ibm.team.interop.manageSyncRules
!ENTRY com.ibm.team.process.rcp.ui 4 0 2011-07-11 15:07:54.750
!MESSAGE Erreur consigne partir de l'interface utilisateur RCP de processus :
!STACK 0
com.ibm.team.repository.client.ServerVersionCheckException: Le serveur auquel vous vous connectez est plus ancien que votre client et donc incompatible. Pour dterminer la version du serveur et tlcharger le client appropri, prenez contact avec votre administrateur systme.
at com.ibm.team.repository.client.internal.TeamRepository.fetchClientVersionJSONObject(TeamRepository.java:1602)
at com.ibm.team.repository.client.internal.TeamRepository.access$0(TeamRepository.java:1591)
at com.ibm.team.repository.client.internal.TeamRepository$5.run(TeamRepository.java:1662)
at com.ibm.team.repository.client.internal.TeamRepository$5.run(TeamRepository.java:1)
at com.ibm.team.repository.client.internal.TeamRepository$3.run(TeamRepository.java:1261)
at com.ibm.team.repository.common.transport.CancelableCaller.call(CancelableCaller.java:79)
at com.ibm.team.repository.client.internal.TeamRepository.callCancelableService(TeamRepository.java:1254)
at com.ibm.team.repository.client.internal.TeamRepository.checkServerVersionMatches(TeamRepository.java:1665)
at com.ibm.team.repository.client.internal.TeamRepository.internalLogin(TeamRepository.java:1445)
at com.ibm.team.repository.client.internal.TeamRepository.login(TeamRepository.java:618)
at com.ibm.team.process.internal.rcp.ui.LoginAction$1.run(LoginAction.java:88)
at org.eclipse.core.internal.jobs.Worker.run(Worker.java:55)
Caused by: com.ibm.team.repository.transport.client.AuthenticationException: CRJAZ0097I La demande d'URL "/jazz/versionCompatibility?clientVersion=3.0.1" a t refuse. Le statut est "Interdit".
at com.ibm.team.repository.transport.client.ClientHttpUtil.executeHttpMethod(ClientHttpUtil.java:421)
at com.ibm.team.repository.transport.client.ClientHttpUtil.executeHttpMethod(ClientHttpUtil.java:290)
at com.ibm.team.repository.transport.client.ClientHttpUtil.executeHttpMethod(ClientHttpUtil.java:204)
at com.ibm.team.repository.transport.client.RestClientConnectionBase.executeMethod(RestClientConnectionBase.java:308)
at com.ibm.team.repository.transport.client.RestClientConnectionBase.doMethod(RestClientConnectionBase.java:182)
at com.ibm.team.repository.transport.client.RestClientConnectionBase.doGet(RestClientConnectionBase.java:123)
at com.ibm.team.repository.transport.client.TeamRawRestServiceClient$RawRestClientConnection.doGet(TeamRawRestServiceClient.java:94)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at com.ibm.team.repository.client.internal.ServiceInterfaceProxy.invokeServiceCall(ServiceInterfaceProxy.java:164)
at com.ibm.team.repository.client.internal.ServiceInterfaceProxy.invoke(ServiceInterfaceProxy.java:88)
at com.ibm.team.repository.client.internal.RawRestServiceClientProxy$RestClientConnectionProxy.invoke(RawRestServiceClientProxy.java:121)
at $Proxy9.doGet(Unknown Source)
at com.ibm.team.repository.client.internal.TeamRepository.fetchClientVersionJSONObject(TeamRepository.java:1594)
... 11 more
Caused by: com.ibm.team.repository.common.PermissionDeniedException: CRJAZ0097I La demande d'URL "/jazz/versionCompatibility?clientVersion=3.0.1" a t refuse. Le statut est "Interdit".
at com.ibm.team.repository.transport.client.ClientHttpUtil.executeHttpMethod(ClientHttpUtil.java:420)
... 26 more

!ENTRY org.apache.commons.httpclient.HttpConnection 2 900 2011-07-11 15:07:54.766
!MESSAGE HttpConnectionManager is null. Connection cannot be released.




Is there anything else to configure to use RTC behind a Reverse-Proxy and a firewall ?