Yes I have had problems with them in the past as well as another website I maintain: http://www.ivirtuaforums.com however like I said in the post above they have now changed their ways.
And finally someone backs me up on WordPress getting money from Bluehost to put their link up, ladydelaluna should get the facts right before saying that its just a tracking url.
I know all hosts have downtime, its whats expected what I was saying that the downtime was disgraceful as it was less than 99%, because if you bother to read their website (http://www.bluehost.com) it says that their uptime is 99% guarented. So again thats not good. They've always had 24/7 support you can either phone them or email them, funny though i've still not got a reply from the email I sent them one day ago. And mate you did not 'receive an email from Matt Heaton' its what we call in the trade 'bulk emailing' basically when you sign up to Bluehost they ask for your email, this goes onto a database and everytime they need to inform customers about somthing they email everyone on that list with the same email.
I know that most hosting companies that share servers with multiple users are expected to have problems. And once more, Im really getting pissed off with this, I AM NOT RANTING ABOUT BLUEHOST!!! I AM INFORMING WORDPRESS USERS ABOUT BLUEHOST!!!! IF YOU CARE TO READ THE TOPIC!!! (I MEAN ALL OF IT) YOU WILL SEE THAT I INFORMED USERS THAT DOWNTIME IS NOW ACCEPTABLE!! (Now that was a rant!)
Oh and one last thing: you said, and I state: 'For the price you can't beat it.' You can actually try 1and1.com they are very good! 50GB webspace for 16 (GBP) per year, now thats great, and I bet you they have very, very, very good uptime.