Backup and deploy on a new server "Creating default object from empty value" warning, can't verify.

I'm moving my sites to a new server. - I have a fresh Aegir 2.1 (with nginx) - I've moved old d7 platform (without sites) from an Aegir 1.9 setup to the 2.1, verified the it and can create new sites on it. - I've created a backup in aegir on the old server and transferred it across, and I'm using provision deploy to restore the backup to the moved platform. You know the drill. - Provision save and deploy on a site appear to work without a hitch. Verifying the platform causes the site import to appear in the front end and whilst this apparently completes successfully it does have an 'undefined index' warning:

Calling hook drush_provision_drupal_pre_provision_verify
Found install profile minimal
Found install profile standard
Undefined index: default provision_drupal.drush.inc:611
Creating default object from empty value provision_drupal.drush.inc:612
Found 171 modules
Found 19 themes

If I then try to verify the site the same error occurs. I also can't clone or migrate this site, on a clone (to the same platform) I get this error:

Use of undefined constant NODE_PUBLISHED - assumed 'NODE_PUBLISHED' comment.inc:26
Use of undefined constant NODE_PUBLISHED - assumed 'NODE_PUBLISHED' node.inc:22
Drush command terminated abnormally due to an unrecoverable error. Error: Call to undefined function node_types_rebuild() in /var/aegir/platforms/d7-old/includes/common.inc, line 7475

The web site itself appears to operate normally (the site name after import changed to the domain name repeated several times...odd but the only apparent problem).

I know I'm pushing my luck by trying to make the jump from Aegir 1.9 to 2.1 whilst migrating the site, but does anyone have any suggestion on debugging what is actually going wrong?

The old server is IIRC too ancient to run a more recent version of Aegir. I think my best option if I can't resolve this will be an entirely manual recreation of the site on the new server. Tedious but possible...