I use twitter tools to post my twitter tweets to my blog; the thing is that twitter can sometimes slow down or break completely, this in turn kills wordpress.

To improve things I've changed how often I check twitter, you can do the same by editing the plugin file (wordpress/wp-content/plugins/twitter-tools/twitter-tools.php), see below for a code snippet...

function tweet_download_interval() { #return 1800; return 14400; }
Enjoy!