Troubles with http server on linux
It looks like that you have problems with DNS. can you check this idea running host 192.168.1.100 on the host? Please also check that other DNS queries being quickly processed. 
Check /etc/hosts file for a quick-and-dirty solution.
I have such problem. I have local http server (BottlePy or Django), and when i use http:// localhost/ or http:// 127.0.0.1/ - it loads immediately. But when i use my local ip (192.168.1.100), it loads very long time (some minutes). What could be the problem?
Server works on Ubuntu 11.