Comment 14 for bug 863741

I'm seeing the same thing on a system recently upgraded directly from 10.04 to 12.04. Here's the debugging output:

# apt-get -oDebug::PkgProblemResolver=1 dist-upgrade
Reading package lists... Done
Building dependency tree
Reading state information... Done
Calculating upgrade... Starting
Starting 2
Investigating (0) rpcbind [ i386 ] < none -> 0.2.0-7ubuntu1.2 > ( net )
Broken rpcbind:i386 Conflicts on portmap [ i386 ] < 6.0.0-1ubuntu2.2 > ( net )
  Considering portmap:i386 1 as a solution to rpcbind:i386 1
  Holding Back rpcbind:i386 rather than change portmap:i386
Investigating (0) nfs-common [ i386 ] < 1:1.2.0-4ubuntu4.2 -> 1:1.2.5-3ubuntu3.1 > ( net )
Broken nfs-common:i386 Depends on rpcbind [ i386 ] < none -> 0.2.0-7ubuntu1.2 > ( net ) (>= 0.2.0-6ubuntu1)
  Considering rpcbind:i386 1 as a solution to nfs-common:i386 1
  Holding Back nfs-common:i386 rather than change rpcbind:i386
Investigating (0) nfs-kernel-server [ i386 ] < 1:1.2.0-4ubuntu4.2 -> 1:1.2.5-3ubuntu3.1 > ( net )
Broken nfs-kernel-server:i386 Depends on nfs-common [ i386 ] < 1:1.2.0-4ubuntu4.2 -> 1:1.2.5-3ubuntu3.1 > ( net ) (= 1:1.2.5-3ubuntu3.1)
  Considering nfs-common:i386 1 as a solution to nfs-kernel-server:i386 0
  Holding Back nfs-kernel-server:i386 rather than change nfs-common:i386
 Try to Re-Instate (1) nfs-common:i386
 Try to Re-Instate (1) nfs-kernel-server:i386
Done
Done
The following packages have been kept back:
  nfs-common nfs-kernel-server
0 upgraded, 0 newly installed, 0 to remove and 2 not upgraded.