I have reproduced the network-manager crash and networking being disabled issue with upgrades using jaunty's update-manager, 1:0.111.7, and can confirm that the version of update-manager in jaunty-proposed, 1:0.111.8, fixes the issue, and that networking continues to work throughout the upgrade.
I have reproduced the network-manager crash and networking being disabled issue with upgrades using jaunty's update-manager, 1:0.111.7, and can confirm that the version of update-manager in jaunty-proposed, 1:0.111.8, fixes the issue, and that networking continues to work throughout the upgrade.