Vista fails on link that XP opens correctly

I have a link on a web site that I cannot open when using Windows Vista but which I can open when running Win XP,  Home or Pro.  This situation occurs whether I am using IE latest version or Foxfire latest version. 

The failure occurs on a new Dell Inspiron 1525 running Vista, SP1, current on all updates.
Success occurs on two machines: one is a Dell Dimension 8300 desktop running XP Home (SP2), the other is an IBM Thinkpad T43 running XP Pro (SP3).

The site containing the odd link is a Computer Associates software support page at
http://crm.my-etrust.com/login.asp?username=guest&target=DOCUMENT&openparameter=3125
The link is under the heading "Fix" in the line
"1. Please click here to run the uninstaller for CA Internet Security Suite"

When I "click here" I see an error message  
"An error has occurred: null : generated by notifyWhenSSExeRunning "
on what looks like a page the CA software is composing.  They have some buttons displayed, the one called "close" does close the window.

So the question is--what's going on that my new Dell running Vista errors out here but my 2 or 3 year old other machines running XP just do the job?  And what do I look at to get this new machine working as it should?

A puzzle.