when a ups doesn't help

Had a customer plug a monitor power cord into same rack power strip
that i5 was plugged into. This is a regular professional rack with built in 
power
strips. The whole rack, with i5, is covered by a large ups. Power strip 
"blinked" (some 
kind of electrical short) and next thing we know, i5 is IPLing. The system value
is set to re-ipl when power restored, so it did. Came up fine, but management 
asking how to avoid this. 
Is it common to use a large ups for multiple equipment,
or do most shops with comm, wintel servers, and i5 isolate the i5 on a separate 
ups? 
(and that ups would have to be within power cord distance from server)
jim franz