database error:[Got a packet bigger than ‘max_allowed_packet’]

hello
wordpress takes a long time to load and throws an error:

WordPress database error: [Got a packet bigger than 'max_allowed_packet']
INSERT INTO wp_options (option_name, option_value, option_description, autoload) VALUES ('rewrite_rules', 'a:6809:{s:11:\"robots.txt$\";s:18:\"index.php?robots=1\";s:12:\"wp-atom.php$\";s:19:\"index.php?feed=atom\";s:11:\"wp-rdf.php$\";s:18:\"index.php?feed=rdf\";s:11:\ ... continuing for a long time ... '', 'yes')

yet the page loads fine underneath. message boards suggest one should increase the mysql data bandwith. nothing was changed on the server and i doubt, the bandwith is too short. it looks to me wordpress is doing something i don’t want. trying to trace back what it its attempt is, i found out, there is no option_name called rewrite_rules in table wp_options.

does anyone get what it wants to do?
we are running wp 2.2 and want to upgrade to 2.6. is it safe to upgrade with that error?

thank you
f