When upgrading WordPress to 2.9 on our Cloud Hosting service, you may run into a problem where the upgrade appears to stall at the point where it is downloading the update. Checking your PHP error log can tell you what problem you are having. If you see an error similar to:
PHP Fatal error: Allowed memory size of 33554432 bytes exhausted (tried to allocate 2515174 bytes) in /mnt/stor1-wc1-dfw1/123456/123456/www.domain.com/web/content/wordpress/wp-includes/http.php on line 1331
This probably indicates that you will need to increase the memory_limit value set in PHP. We have instructions on how to increase the memory_limit variable in our FAQ. We recommend setting this to 48M for WordPress to function normally. Once you increase the limit, try your upgrade again. As always, please contact us if you have any questions about upgrading.