about error 10060 "Connection timeout" from Internet Explorer



Now, My server is running ISA server 2000 Enterprise on Windows 2003
Server,My Company is using ADSL connection to connect Internet and recieve
Internet Email. Recently, Internet Explorer on Client's workstation usually
display "error 10060 Conection timeout" and display White page, But then
when Users click "refresh" button, this content of Website can display (this
error happen on many many website). I don't think ADSL connection is problem
or These websites are overload can cause that error, because it happen many
times a day, and occur on many many website and repeat day after day . I
suspect my ISA Server is error but don't know Why the reasons are ? please
help me to correct it. Thanks a lot


.