I have a Ubuntu 11.04 (amd64) PC with DRBL server on it. I set it to provide Clonezilla in partition restore mode. Client PCs do boot in PXE and DRBL menu is shown but the Clonezilla menu item won't work at all - nothing happens except a little screen flickering. At the same time, netinstall mode appears to work just fine, as well as memtest and local boot options.
Here is a screenshot of a client VM: http://i.stack.imgur.com/naEkj.png
Same goes for physical PCs. Neither automatic nor manual Clonezilla boot proceed. What's wrong with my setup?