From what i can tell i think that CT did not store any info in the db in D5 but in D6 the intent is to store the info in a std cck table. Is this correct?

My guess is that update 6000 is meant to create and populate new content_field_ tables with data previously only stored in the standard term_node table.

it appears as though only the child terms of a multiselect hierarchical vocabulary get copied over to this new cck table.

To make this a little tricker to track down it seems as though the CT cck Views handler still uses term_node data rather than this new cck table (perhaps this should be a separate issue??). Since i was still able to filter nodes by filtering on a parent term when that term is not listed as being selected when i go to edit the node.

One further bug is that the multiselect widget for this field is no longer showing the hierarchy as it did in D5.