I have encountered this in numerous versions, 6.x-2.x-dev being the latest. On editing a node, an error displays:
user warning: Table 'mydb.xmlsitemap_node' doesn't exist query: SELECT priority_override FROM xmlsitemap_node WHERE nid = 128188 in /var/www/vhosts/mysite.com/httpdocs/sites/default/modules/xmlsitemap/xmlsitemap_node/xmlsitemap_node.module on line 226.
Its clear from checking the tables in the db and the install files for both xmlsitemap and xmlsitemap_node (which is version 6.12??) that the table is never created, and in fact there is an old update in xmlsitemap_node.install explicitly dropping the table.
I have tried using an old backup to recreate the table, but a 'changed' column is apparently missing.
Can we get some xmlsitemap node love?