that's because the page size is too big(~6M).
this can explain why "Req In Process >> Req / sec". the web server have to take much time to read 6M from disk to serve a single request to homepage(and subsequent requests, img/js/css etc). So it keeps reading.
@NiteWave: All images are external. I understand a lot needs to be done code wise to help increase the speed. Thats not really the issue.
The other day (although it has stopped now) it seemed to be a minute or so before the page started loading. There were no network issues and no load issues on the server. It seemed to just be how many people could be served at one time