jk3210 - 4:57 pm on May 18, 2011 (gmt 0)
I have the same problem as edacsac.
On one set-up I have one main site and 4 add-on sites. All five are WP. The add-on sites usually run fine, but the main site is similar to what edacsac describes. (Not nearly as bad, but similar).
What is REALLY strange is this: When the site does hang and fail to load (white screen with the "wait cursor" spinning), if I hit the "stop" button in FF and do a View --> Page Source, the ENTIRE HTML is there! Everything right down to the bottom comment that says "<!--WP-Super Cache loaded in 1.745 seconds" is all there. The HTML is there, but the site won't display. Then for the next 2 or 3 hours the site runs fine and loads in 2-5 seconds.
Techs from my ISP (HG) have been all over the site numerous times and found no problems.
GA "Site Speed" reports various page load times from 2-seconds up to 43-seconds.
I've tried: WP-Super Cache, W3TC, and now Hyper Cache. Same intermittent problem.
I'd go for a Ded server in a heartbeat if I thought that would solve the problem, but I'm not sure it would.