I find it a little hard to believe that no one here has asked this question, I tried searching for it but it isn't asked, so here goes:
I setup a Ubuntu desktop computer with VNC to use as a server. And use another Ubuntu desktop computer to VNC into it. The rest of the VNC works ok, but drag and drop with mouse is gone. Thus I can not move windows, or drag and drop items via VNC.
I am using the default remote desktop in System - Preferences to setup my server. And use Remmina as my client. The same happens using MS Windows's VNC clients connecting to my Ubuntu desktop.
I did a bit of searching on google, and there are actually a lot of reports regarding this issue. But, oddly there is no solution. There are even bug reports made for this since Ubuntu 9.10, yet here it still is in Ubuntu 11.04. There have been suggestions that the bugs is in gtk, as see in link below:
http://ubuntuforums.org/showthread.php?t=1497635&page=2
libgtk2.0-0 stable(lenny) -> DnD works
libgtk2.0-0 lenny-backport (libgtk2.0-0_2.18.6-1~bpo50+1_i386) -> DnD still works
libgtk2.0-0 testing (libgtk2.0-0_2.20.1-2_i386) -> DnD broken
please don't give answers such as "use NX", "use ssh -x" or "use x11vnc". I am aware that some people don't have this problem with x11vnc, and I have setup x11vnc before, but i can't for this setup. I am setting this up so Windows only friends/families can use it.