... we use Open-E, vSphere 4.0 and Veeam Backup since nealry one month in production, and it works like a charme. If you just mount the iSCSI LUNs in the system Veeam is running on, like for instance Windows XP with the use of te MS iSCSI Iniator, everything works just fine.

No changes on ESXi and no changes on Open-E. Just add the Veeam, and it works perfectly...

greetz