[TYPO3] "cache_pagesection" return errors in FE

[Peter Klein]

Hi List. I have a problem on a site, where some FE users (I haven't been 
able to duplicate the error myself) get's this error msg.
-- cut --
INSERT INTO cache_pagesection
(
page_id,
mpvar_hash,
content,
tstamp
) VALUES (
'4',
'222419149',
'a:4:{s:3:\"all\";a:2:{s:32:\"338e394457c2db162483324451f05ded\";s:23:\"[compatVersion 
= 3.9.0]\";s:32:\"41428859d35690400a615c4ebfa39dc3\";s:15:\"[loginUser = 
*]\";}s:6:\"rowSum\";a:11:{i:0;a:3:{i:0;s:1:\"2\";i:1;s:8:\"NEW 
SITE\";i:2;s:10:\"1162234447\";}i:1;a:3:{i:0;s:24:\"cssstyledcontent/static/\";i:1;s:30:\"EXT:css_styled_content/static/\";i:2;N;}i:2;a:3:{i:0;s:21:\"discusjob/pi1/static/\";i:1;s:26:\"EXT:discus_job/pi1/static/\";i:2;N;}i:3;a:3:{i:0;s:11:\"newloginbox\";i:1;s:11:\"newloginbox\";i:2;N;}i:4;a:3:{i:0;s:13:\"makeprintlink\";i:1;s:14:\"make_printlink\";i:2;N;}i:5;a:3:{i:0;s:13:\"pdfgenerator2\";i:1;s:14:\"pdf_generator2\";i:2;N;}i:6;a:3:{i:0;s:8:\"tvpdfgen\";i:1;s:9:\"tv_pdfgen\";i:2;N;}i:7;a:3:{i:0;s:1:\"1\";i:1;s:13:\"Main 
Template\";i:2;s:10:\"1165227489\";}i:8;a:3:{i:0;s:24:\"cssstyledcontent/static/\";i:1;s:30:\"EXT:css_styled_content/static/\";i:2;N;}i:9;a:3:{i:0;s:1:\"3\";i:1;s:13:\"Logo 
Template\";i:2;s:10:\"1162242644\";}i:10;a:3:{i:0;s:1:\"4\";i:1;s:13:\"Menu 
Template\";i:2;s:10:\"1161948082\";}}s:5:\"match\";a:2:{s:32:\"338e394457c2db162483324451f05ded\";s:23:\"[compatVersion 
= 3.9.0]\";s:32:\"41428859d35690400a615c4ebfa39dc3\";s:15:\"[loginUser = 
*]\";}s:8:\"rootLine\";a:2:{i:0;a:27:{s:3:\"pid\";s:1:\"0\";s:3:\"uid\";s:1:\"1\";s:9:\"t3ver_oid\";s:1:\"0\";s:10:\"t3ver_wsid\";s:1:\"0\";s:11:\"t3ver_state\";s:1:\"0\";s:14:\"t3ver_swapmode\";s:1:\"0\";s:5:\"title\";s:16:\"Discus 
Jobcenter\";s:5:\"alias\";s:0:\"\";s:9:\"nav_title\";s:0:\"\";s:5:\"media\";s:0:\"\";s:6:\"layout\";s:1:\"0\";s:6:\"hidden\";s:1:\"0\";s:9:\"starttime\";s:1:\"0\";s:7:\"endtime\";s:1:\"0\";s:8:\"fe_group\";s:0:\"\";s:16:\"extendToSubpages\";s:1:\"0\";s:7:\"doktype\";s:1:\"1\";s:8:\"TSconfig\";s:0:\"\";s:11:\"storage_pid\";s:1:\"2\";s:11:\"is_siteroot\";s:1:\"0\";s:9:\"mount_pid\";s:1:\"0\";s:12:\"mount_pid_ol\";s:1:\"0\";s:13:\"fe_login_mode\";s:1:\"0\";s:17:\"tx_templavoila_ds\";s:1:\"1\";s:17:\"tx_templavoila_to\";s:1:\"1\";s:22:\"tx_templavoila_next_ds\";s:1:\"1\";s:22:\"tx_templavoila_next_to\";s:1:\"1\";}i:1;a:27:{s:3:\"pid\";s:1:\"1\";s:3:\"uid\";s:1:\"4\";s:9:\"t3ver_oid\";s:1:\"0\";s:10:\"t3ver_wsid\";s:1:\"0\";s:11:\"t3ver_state\";s:1:\"0\";s:14:\"t3ver_swapmode\";s:1:\"0\";s:5:\"title\";s:12:\"Udtræksmodul\";s:5:\"alias\";s:0:\"\";s:9:\"nav_title\";s:0:\"\";s:5:\"media\";s:0:\"\";s:6:\"layout\";s:1:\"0\";s:6:\"hidden\";s:1:\"0\";s:9:\"starttime\";s:1:\"0\";s:7:\"endtime\";s:1:\"0\";s:8:\"fe_group\";s:1:\"1\";s:16:\"extendToSubpages\";s:1:\"0\";s:7:\"doktype\";s:1:\"1\";s:8:\"TSconfig\";s:0:\"\";s:11:\"storage_pid\";s:1:\"0\";s:11:\"is_siteroot\";s:1:\"0\";s:9:\"mount_pid\";s:1:\"0\";s:12:\"mount_pid_ol\";s:1:\"0\";s:13:\"fe_login_mode\";s:1:\"0\";s:17:\"tx_templavoila_ds\";s:1:\"0\";s:17:\"tx_templavoila_to\";s:1:\"0\";s:22:\"tx_templavoila_next_ds\";s:1:\"0\";s:22:\"tx_templavoila_next_to\";s:1:\"0\";}}}',
'1165243979'
)
-- cut --

does anyone know WHY this is happening, and HOW to prevent it?

-- 
Peter Klein/Umloud Untd