People have reported issues with the way the upgrade process in 3.3 works.
Currently, the upgrade queries are called like so:
foreach ($revisions['3.x'] as $revision) {
if (DB_VER < $revision) {
$method = "v{$revision}";
v3xUpgrades::{$method}($db);
}
}
This should be changed so that the v3xUpgrades::{$method}
isn't needed and solves the issue.