During the past several months, I've had a little trouble with SuperGeekery, which is built on Expression Engine. I would often get blank white screens if I clicked through the site too quickly. I think this was always when I was logged in as a SuperAdmin and using the control panel. Asking site visitors, I don't know that anyone else was having the problem, but it happened to me regularly. I could also only get this to happen using Safari.
Using other browsers, like Firefox didn't produce the error, but it would do something similar, like not refreshing the page at all.
After researching the issue, I came across this post on Get Satisfaction in regard to an AddOn made by the wonderful Pixel & Tonic, makers of fine EE extensions. The post didn't deal with the problem I had directly. I don't use the add ons they are talking about, but I was having the white screen problem.
Although it's far from scientific, I guessed that I may be running out of memory on my server. I had a basic shared hosting environment from Dreamhost and it has served me well for many years. I put it through the ringer though. I get my money's worth out of the shared hosting plan. I thought maybe I had reached the limit of what it could provide. Luckily, they provide virtual private servers that you can switch to with a single button click. (You can read about them here.) To find out if that could be my issue, I switched over. It would allow me to get a picture of how many resources SuperGeekery was taking.
I switched over both the hosting and the MySQL hosting, waited a few hours. There were a few server paths in my configuration I had to change for the Expression Engine installation to work. (Specifically, you need to change "/home/.SOMETHING/username" or "/mnt/local/home/username" to be just "/home/username".)
The white screens disappeared for me. My site seems to be loading much faster as well. After a day, I logged into my control panel and here's below is a screenshot of what I saw.
You can see the moment I installed the software onto the server, the memory usage started to go up. I'm not really hitting the CPU that hard, I think that's because I've got quite a lot of caching going on in the site. Those spikes in the memory usage though, I think may coincide with when I'm mucking around in the site. It also seems to be averaging around 185 megabytes of usage, spiking over 200 at times. With more memory available, the site seems to be working much better.