Matt,
Where are you installing iXp? Both UAT and PROD on the same box?
If so, ensure the following things:
The autouser for both instance exists on the box and the path provided in the admin utility with their DB credentials are correct.
Also ensure the permissions and owner/group is autosys:autosys.
One new thing I found on SP8 is, when a change is made in the admin utility, you have to restart tomcat.