Internet Explorer Proxy connection problem

I have a program that manually changes a users Internet Explorer proxy server settings (under the IE menu for Tools -> Interent Options -> Connections -> LAN Settings). All users have either cable or dsl.

The program causes the IE checkbox for "use proxy server" to be checked, and enters the proxy server address in the boxes for "Address" and "Port".

This works everytime -- the program never fails to automatically set that info.

But about 10 percent of the time it has no effect -- meaing the proxy info is entered, but Internet Explorer does not use the proxy server. The users connection to the Internet remains the same (their direct connection, not a proxy connection).

That is the problem.. I need to figure out how to get the users Internet Explorer to use the proxy.


THANKS FOR READING