CRJAZ0098I error - able to access via browser, not Eclipse

Hi

We are using RTC v3.0 on a Windows 2003 machine with SQL Server.
Since yesterday and we have a problem, that we can access RTC using the browser, but not via the Eclipse client any more.

Like in thread https://jazz.net/forums/viewtopic.php?t=17176&highlight=crjaz0098i the problem occurs when we try to connect to a repository or create a new repository connection:
Not like in the thread mentioned above the server returns the HTTP error 500 with error text "Internal Server Error".

com.ibm.team.repository.common.transport.TeamServiceException: CRJAZ0098I The "com.ibm.team.repository.common.internal.IRepositoryRemoteService{/jazz/service/com.ibm.team.repository.common.internal.IRepositoryRemoteService}" service failed. The server returned the HTTP error 500 with error text "Internal Server Error".
at com.ibm.team.repository.transport.client.ClientHttpUtil.throwHttpClientError(ClientHttpUtil.java:1191)
at com.ibm.team.repository.transport.client.ClientHttpUtil.executeHttpMethod(ClientHttpUtil.java:420)
at com.ibm.team.repository.transport.client.ClientHttpUtil.access$8(ClientHttpUtil.java:276)
at com.ibm.team.repository.transport.client.ClientHttpUtil$JAuthChallengeHandler.handleChallenge(ClientHttpUtil.java:637)
at com.ibm.team.repository.transport.client.ClientHttpUtil.handleAuthenticationChallenge(ClientHttpUtil.java:1038)
at com.ibm.team.repository.transport.client.ClientHttpUtil.executeHttpMethod(ClientHttpUtil.java:311)
at com.ibm.team.repository.transport.client.ClientHttpUtil.executeHttpMethod(ClientHttpUtil.java:269)
at com.ibm.team.repository.transport.client.ClientHttpUtil.executeHttpMethod(ClientHttpUtil.java:183)
at com.ibm.team.repository.transport.client.RemoteTeamService.executeCancelableHttpMethod(RemoteTeamService.java:575)
at com.ibm.team.repository.transport.client.RemoteTeamService.invokePost(RemoteTeamService.java:545)
at com.ibm.team.repository.transport.client.RemoteTeamService.executeMethod(RemoteTeamService.java:485)
at com.ibm.team.repository.transport.client.RemoteTeamService.invoke(RemoteTeamService.java:202)
at com.ibm.team.repository.transport.client.ServiceInvocationHandler.invoke(ServiceInvocationHandler.java:43)
at $Proxy1.describe(Unknown Source)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:79)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:618)
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 $Proxy1.describe(Unknown Source)
at com.ibm.team.repository.client.internal.TeamRepository$4.run(TeamRepository.java:1486)
at com.ibm.team.repository.client.internal.TeamRepository$4.run(TeamRepository.java:1)
at com.ibm.team.repository.client.internal.TeamRepository$3.run(TeamRepository.java:1260)
at com.ibm.team.repository.common.transport.CancelableCaller.call(CancelableCaller.java:79)
at com.ibm.team.repository.client.internal.TeamRepository.callCancelableService(TeamRepository.java:1253)
at com.ibm.team.repository.client.internal.TeamRepository.internalLogin(TeamRepository.java:1479)
at com.ibm.team.repository.client.internal.TeamRepository.login(TeamRepository.java:617)
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)

We do not see any error logs on the server or any services which are not running.

Any ideas?

Ulrich