Redundant FSP's: How to check the firmware version

I am "assuming" that with redundant FSP's that there is some way to update 
the firmware in one FSP or the other without disrupting the whole system. 
Anyone have any idea how this works?  Here's the situation.  I finally got 
our redundant FSP's to work (by help of our CE in Fort Wayne IN and a "top 
gun" named Stan out of Indianapolis).  If I right click on the system and 
select the bottom Status option it now shows that redundant fsp's are 
active and what they're IP addresses are.  But nothing about firmware 
levels.  So I go into update, yadda, view current levels and it only shows 
me one level.  Am I mistaken?  Are firmware upgrades still disruptive?

Rob Berendt