HTTP server page refresh problem

I am encoutering a webserver refresh problem with NETOS6.0. I run the sample project “nahttp” comes with NETOS6.0. The pages loading seems okay…not if I keep refreshing the page by clicking the browser refresh/reload button. The webserver will simply fail to load pages anymore after some times of reload. This is happening both in debug mode and standalone run mode. However when the webserver fails it still “ping-able”. Anyone has similar experience? I didn’t notice this problem when I had NETOS5.0 running before.