Cannot Check-In Websphere BPM Model Changes

I try to use RTC SCM (2.0.0.2) for BPM Models.
Mostly, when i try to check-in changes, it fails to upload.

It says: "Checking has encountered a problem", Failed to upload files.

The log gives some more detail:

!SUBENTRY 1 com.ibm.team.filesystem.client 4 0 2011-05-03 16:42:05.779
!MESSAGE Error during upload
!SUBENTRY 2 com.ibm.team.filesystem.client 4 0 2011-05-03 16:42:05.779
!MESSAGE Failed to upload File /ModelingProject/messages.xmi
!STACK 0
com.ibm.team.repository.common.TeamRepositoryException: Error uploading new contents of /ModelingProject/messages.xmi
at com.ibm.team.filesystem.client.internal.operations.CheckinUploadHandler.init(Unknown Source)
at com.ibm.team.filesystem.client.internal.operations.CheckinUploadHandler.getPredecessorHintHash(Unknown Source)
at com.ibm.team.scm.client.content.BasicAsyncVersionedContentManagerSession.internalDoStoreContent(Unknown Source)
at com.ibm.team.scm.client.content.BasicAsyncVersionedContentManagerSession$3.run(Unknown Source)
at com.ibm.team.repository.client.util.ThreadPool$PoolJob.run(Unknown Source)
at org.eclipse.core.internal.jobs.Worker.run(Unknown Source)
Caused by: com.ibm.team.filesystem.client.FileSystemClientException: Status ERROR: com.ibm.team.filesystem.client code=0 Unable to determine properties for /ModelingProject/messages.xmi org.eclipse.core.internal.resources.ResourceException: Resource is out of sync with the file system: '/ModelingProject/messages.xmi'. children=, , , ,
]
at com.ibm.team.filesystem.rcp.core.internal.resources.ResourceContentExaminer.getContentProperties(Unknown Source)
at com.ibm.team.filesystem.rcp.core.internal.resources.ResourceContentExaminer.findStoredProperties(Unknown Source)
... 6 more
Caused by: org.eclipse.core.internal.resources.ResourceException: Resource is out of sync with the file system: '/ModelingProject/messages.xmi'.
at org.eclipse.core.internal.resources.File.checkSynchronized(Unknown Source)
at org.eclipse.core.internal.resources.File.getContentDescription(Unknown Source)
at com.ibm.team.filesystem.rcp.core.internal.resources.ResourceUtil.getContentTypeFor(Unknown Source)
... 8 more
!SUBENTRY 1 com.ibm.team.filesystem.client 4 0 2011-05-03 16:42:05.779
!MESSAGE Error during upload
!SUBENTRY 2 com.ibm.team.filesystem.client 4 0 2011-05-03 16:42:05.779
!MESSAGE Failed to upload File /ModelingProject/messages.xmi
!STACK 0
com.ibm.team.repository.common.TeamRepositoryException: Error uploading new contents of /ModelingProject/messages.xmi
at com.ibm.team.filesystem.client.internal.operations.CheckinUploadHandler.init(Unknown Source)
at com.ibm.team.filesystem.client.internal.operations.CheckinUploadHandler.getPredecessorHintHash(Unknown Source)
at com.ibm.team.scm.client.content.BasicAsyncVersionedContentManagerSession.internalDoStoreContent(Unknown Source)
at com.ibm.team.scm.client.content.BasicAsyncVersionedContentManagerSession$3.run(Unknown Source)
at com.ibm.team.repository.client.util.ThreadPool$PoolJob.run(Unknown Source)
at org.eclipse.core.internal.jobs.Worker.run(Unknown Source)
Caused by: com.ibm.team.filesystem.client.FileSystemClientException: Status ERROR: com.ibm.team.filesystem.client code=0 Unable to determine properties for /ModelingProject/messages.xmi org.eclipse.core.internal.resources.ResourceException: Resource is out of sync with the file system: '/ModelingProject/messages.xmi'. children=, , , ,
]
at com.ibm.team.filesystem.rcp.core.internal.resources.ResourceContentExaminer.getContentProperties(Unknown Source)
at com.ibm.team.filesystem.rcp.core.internal.resources.ResourceContentExaminer.findStoredProperties(Unknown Source)
... 6 more
Caused by: org.eclipse.core.internal.resources.ResourceException: Resource is out of sync with the file system: '/ModelingProject/messages.xmi'.
at org.eclipse.core.internal.resources.File.checkSynchronized(Unknown Source)
at org.eclipse.core.internal.resources.File.getContentDescription(Unknown Source)
at com.ibm.team.filesystem.rcp.core.internal.resources.ResourceUtil.getContentTypeFor(Unknown Source)
... 8 more

!ENTRY com.ibm.team.filesystem.client 4 0 2011-05-03 16:42:05.794
!MESSAGE Failed to upload File /ModelingProject/messages.xmi
!STACK 0
com.ibm.team.repository.common.TeamRepositoryException: Error uploading new contents of /ModelingProject/messages.xmi
at com.ibm.team.filesystem.client.internal.operations.CheckinUploadHandler.init(Unknown Source)
at com.ibm.team.filesystem.client.internal.operations.CheckinUploadHandler.getPredecessorHintHash(Unknown Source)
at com.ibm.team.scm.client.content.BasicAsyncVersionedContentManagerSession.internalDoStoreContent(Unknown Source)
at com.ibm.team.scm.client.content.BasicAsyncVersionedContentManagerSession$3.run(Unknown Source)
at com.ibm.team.repository.client.util.ThreadPool$PoolJob.run(Unknown Source)
at org.eclipse.core.internal.jobs.Worker.run(Unknown Source)
Caused by: com.ibm.team.filesystem.client.FileSystemClientException: Status ERROR: com.ibm.team.filesystem.client code=0 Unable to determine properties for /ModelingProject/messages.xmi org.eclipse.core.internal.resources.ResourceException: Resource is out of sync with the file system: '/ModelingProject/messages.xmi'. children=, , , ,
]
at com.ibm.team.filesystem.rcp.core.internal.resources.ResourceContentExaminer.getContentProperties(Unknown Source)
at com.ibm.team.filesystem.rcp.core.internal.resources.ResourceContentExaminer.findStoredProperties(Unknown Source)
... 6 more
Caused by: org.eclipse.core.internal.resources.ResourceException: Resource is out of sync with the file system: '/ModelingProject/messages.xmi'.
at org.eclipse.core.internal.resources.File.checkSynchronized(Unknown Source)
at org.eclipse.core.internal.resources.File.getContentDescription(Unknown Source)
at com.ibm.team.filesystem.rcp.core.internal.resources.ResourceUtil.getContentTypeFor(Unknown Source)
... 8 more