My Drupal 7 site has many error notices like
Notice: unserialize() [function.unserialize]: Error at offset 225 of 305 bytes in variable_initialize() (line 943 of /site/includes/bootstrap.inc).
Call-time pass-by-reference has been deprecated in drupal_load() in bootstrap.inc
The site still works inspite of the errors. Is it okay to ignore these error notices?