OPNQRYF after 5.1

I've got a client that has an OPNQRYF that at v4r5 was approx 1sec for all
users.
After upgrading to v5r1 selected offices are getting 3-4sec response with the
rest getting approx 1sec response. The programmer says same program in all
cases...

I did a strdbmon *detail while the programmer ran it as a fast location and then
ended and restarted dbmon and captured the data with the programmer running like
a slow office.

What I found:
#1 excluding the start/stop dbmon cmd the fast office captured 3 lines
#2 excluding the start/stop dbmon cmd the SLOW office captured 18 lines
#3the slow office has 15s line dealing with TRIGGERS, then the OPNQRYF same as
the fast office.

Monday we are going run it in debug and see what we can see but I would like
some more ammo as well. I know what triggers are and basically what they are
used for.
How would you go about tracking down this problem?