XML Sitemap module slows down mysqld and finally kills it

Hi,

after using Google sitemap for some time without any problems, a few days ago I switched to XML Sitemap; the Google Sitemap module was uninstalled by (a) deactivating the module, (b) uninstalling it by using the "uninstall" feature, and finally (c) deleting the contents in the module directory. Afterwards, the XML Sitemap module was installed by (a) copying the contents of the archive file into the modules subdirectory, (b) enabling it, and (c) running update.php, just in case. No configuration was done in the settings, thus the module basically should just sit there and wait for sometheing to be told.

After running the site with enabled XML Sitemap module for a few hours, it starts to inject SQL queries into mysqld, e.g.:

INSERT INTO xmlsitemap_node (nid, pid, last_changed, last_comment, previous_comment) SELECT n.nid, ua.pid, n.changed, s.last_comment_timestamp, MAX(c.timestamp) FROM node n LEFT JOIN node_comment_statistics s ON s.nid = n.nid LEFT OUTER JOIN comments c ON c.nid = n.nid AND c.timestamp < s.last_comment_timestamp LEFT JOIN xmlsitemap_node xn ON xn.nid = n.nid LEFT JOIN url_alias ua ON ua.src = CONCAT('node/', n.nid) WHERE xn.nid IS NULL GROUP BY n.nid, ua.pid, n.changed, s.last_comment_timestamp

(Monitored with mytop). These queries run for hours, seem to multiply and then tend to use up all CPU resources (dual core!) until mysqld dies or the site becomes inaccessible. This seems to happen faster and get worse if I configure XML Sitemap to submit notifications during node creation oder cron runs (I didn't survey this in depth but undid all configurations of the module after I had the restart mysqld several times in a few hours).

QUESTION: Is this something "normal" that goes away after running for a longer time (like the heavy database activity the module causes immediately after enabling the module), or is there something fishy with the module or my sites? I installed XML Sitemap on five Drupal sites, and all currently show the same behaviour.

System: Debian "Etch", MySQL 5.0.32, Apache 2.2.3, PHP 5.2.0-8+etch9, Drupal 5.6; Dual-Core CPU, AMD Opteron Processor 1212 HE2 GB RAM, ~23.000 nodes on the largest site, the other sites have ~8000-10.000 nodes.

Thanks for any suggestiions,
-asb