Although you can manually type in the information and the job works fine, the drop down panels aren't being populated with any values for folder name, workflow name or start from task fields in job objects.
The likely cause for this behavior is a missing or incorrectly set environment variable.
Check that the following variables and library path are set and/or correct:
INFA_HOME=/app/Informatica/9.x (root location of the informatica client)
INFA_DOMAINS_FILE=/informatica/9.x/domains.infa (location of the domains.infa file)
LIBPATH=$LIBPATH:$INFA_HOME/server/bin (or library path variable appropriate for OS)