Taborious

All, I am having a problem with DNS resolution, here is the setup. I have 3 app servers behind a cisco load balancer. The url that the IP resolves to resolves to the load balancer. I have sites all over the world who access the server 24/7. I have a couple of users in one location that complain that sometimes they can not connect to the servers via the URL but by IP works fine. I have had them run pings and all they get back is "Ping request could not find host" but the ping to the IP retunrs 4 successful replys and they can resolve other DNS addresses ie www.yahoo.com Any ideas?

Guys, I am having the same issue that bluewookie was explaining. Though, my environment is slightly different and I can not use a hosts file for the solution per company policy. This is an enterprise environment, I have 3 app server behind a cisco content switch (basically a load balancer) and the ip address that resolves to the url resolves to the load balancer. At one location in penang, singapore users complain that they sometimes can not connect to the app servers via the url but can always connect via IP. I had a user do some testing and when he tries to ping the url it just says "Ping request could not find host" but ping the IP and of course it works. No other users at any location here or abroad are having this issue. Not sure how bluewookie resolved his issue, any suggestions?