Fatal error upgrading from 3.4.2 to 3.4.4 on multilingual site

When trying to run upgrade script after updating civicrm from v 3.4.2 to 3.4.4 on a multilingual CiviCRM/Drupal 6.22 site, initially got a WSOD. After enabling error display, got the following:

PHP Fatal error: Allowed memory size of 268435456 bytes exhausted (tried to allocate 71 bytes) in /var/www/.../sites/all/modules/civicrm/packages/PEAR.php on line 884, referer: http://.../en/civicrm/admin?reset=1

Tried increasing server memory from 256M to 512M with exactly the same result. Tried disabling all Drupal modules except core and civi core. Same result. After reading topic 20138 on the civicrm forums, I tried reverting to single language, and update worked.