channel security error

I developed an application using flex viewer 3.0. it runs fine on my server. but when i run the same application on the my office
intranet giving the IP address of the application i have received following error:

mymap layer failed to load (my map is name of basemap mentioned in the config file of my application.)
Fault code :Channel.Secruity.Error
Secruity Error using url

any clue what could be the remedy......