hmmm. It may be a hosting thing actually.

if you try to access your "twitter.php" on the blog site, you get this message...

/statuses/user_timeline.xml?screen_name=big_pearl Rate limit exceeded. Clients may not make more than 150 requests per hour.

Either the Rate limit needs to be lifted, or you'll have to come up with ways to reduce the amount of requests going out.

in php, you could write the twitter results to a file on the server. Then when a user goes to the site, your "twitter.php" would look and see if the file is >1 minute old. If so, update it, then serve to flash.