can't open *.jsp page

[mori]

Hi,

Using Win98SE with 128bit IE6
My bank's website login page is
https:\\.......\login.jsp
which I can access without any problem.

I am try to login to the UK's Royal Mail postcode finder at
https://www.royalmail.com/portal/rm/postcodefinder
When I enter my correct email\password it tries to redirect me to this page
royalmail-shared_page_template.jsp
Attempting to access this page IE pops up a file download window to ask what
to do with this file!
Why can't it open this *.jsp page?

tia

mori