by Dan Eliot.
As a FINAL FINAL comment about this...
I moved my Moodle from Dreamhost to a Linode VPS, and everything is great. I think the main difference is that I have 512megs of RAM (guaranteed) on my VPS, and Moodle 2.4 is doing very well with this amount of RAM. Dreamhost won't discuss the amount of RAM a shared hosting user has, but many sources say that shared hosting has under 200megs of RAM.
For what it's worth...