Error message when opening any preview site through Channel Manager

To reproduce:

• Go to the Channel Manager
• Click on the preview link for any channel

Expected: A new window opens with the preview
Actual: A new window opens with the preview, and the following error message shows in the console:

[INFO] [talledLocalContainer] 22.12.2011 09:28:51 WARN [org.apache.cxf.jaxrs.utils.JAXRSUtils.findTargetMethod():407] No operation matching request path "/site/_rp/rep:root/composermode/localhost" is found, Relative Path: /composermode/localhost, HTTP Method: POST, ContentType: /, Accept: /,. Please enable FINE/TRACE log level for more details.
[INFO] [talledLocalContainer] 22.12.2011 09:28:51 WARN [org.apache.cxf.jaxrs.impl.WebApplicationExceptionMapper.toResponse():55] WebApplicationException has been caught : no cause is available