I imported about a thousand terms into the terms_data table and then added the parent-child relationships in the terms_hiearchy table. Everything went smoothly until I tried to add a term manually in another vocabulary using the "add terms" UI in taxonomy.
 
the auto increment for these tables should be over 1000 and is showing as such in phpmyadmin - is that value stored somewhere where I can alter it?
 
If I manually enter terms into the _data and _hierarchy tables, is there something else I need to alter to avoid problems when I go back to manually adding terms?
 
Neil