I've installed it on my two toy websites, Dragon Affairs Test Site and Dragon Affairs Family and Friends. While I was playing around with it, every now and them I'd run into the dreaded White Screen of Death. The only data recorded by Apache was "child pid 2363 exit signal Illegal instruction (4)". It was quite annoying.
After spending a lot of time disabling and re-enabling various modules (with no luck), I started playing with the performance optimizations. When I disabled the "Optimize CSS files" option everything worked normally. Bingo! Something was up with the CSS files.
Well, they looked normal, except when viewed on a UNIX-like system. I run my sites on an old FreeBSD server. The vi editor showed that the lines in each file ended in CRLF instead of the standard LF character. A quick edit (using
tr -d '\r' style.css , and repeating that for each *.css file) and I was back in business. Odd how the littlest of things can cause a complete failure.