Shell, sorry I know you are just back but had it quite often today with issues when loading any page it will randomly display the following:
Fatal error: Uncaught exception 'Exception' with message 'String could not be parsed as XML' in /home/kiramani/public_html/guilds/mongooses/sites/all/modules/cbovard-simple_tweet-a3aad93/simple_tweet.module:201 Stack trace: #0 /home/kiramani/public_html/guilds/mongooses/sites/all/modules/cbovard-simple_tweet-a3aad93/simple_tweet.module(201): SimpleXMLElement->__construct('<?xml version="...') #1 /home/kiramani/public_html/guilds/mongooses/sites/all/modules/cbovard-simple_tweet-a3aad93/simple_tweet.module(79): _simple_tweet_get_twitters() #2 /home/kiramani/public_html/guilds/mongooses/includes/module.inc(462): simple_tweet_block() #3 /home/kiramani/public_html/guilds/mongooses/modules/block/block.module(499): module_invoke() #4 /home/kiramani/public_html/guilds/mongooses/includes/theme.inc(1626): block_list('view', '1') #5 /home/kiramani/public_html/guilds/mongooses/sites/all/themes/tao/template.php(360): theme_blocks() #6 /home/kiramani/public_html/guilds/mongooses/includes/theme.inc(656): tao_blocks('simple_tweet_bl...', in /home/kiramani/public_html/guilds/mongooses/sites/all/modules/cbovard-simple_tweet-a3aad93/simple_tweet.module on line 201
and just hitting refresh normally loads the page. Now I know nothing much from it as I am so simple but hopefully it means something to you 
I noticed that on my iphone not too long ago, i just thought i broke it again.