When making web service calls to core_user_get_users_by_id, we're noticing that some users with timezones of numeric values (such as 10.0) are returning errors. We upgraded from Moodle 2.0.x and those were working fine before using the old moodle_user_get_users_by_id call. The difference seems to be the PARAM checking type, where before it was ALPHANUMEXT, now it is TIMEZONE.