Plugin failed if "WWW-Authentication: Negotiate" is required

[dirkey]

I enable Kerberos authentication on my server. Now the plugin ends up in a 401/200 endless loop by calling .../UIDL/?v-uiId=0. The 401 occures, because there is WWW-Authentication header in the request (with the kerberos token). Then it resends the request with the token (200). Unluckily the request is then repeated.

[mstahv]

Is this related to easyuploads or vaadin itself? Do you have any ideas how this could be reproduced for debugging?