Cron and Dbexport problem.

Until we get a tape drive for our Data General box, I am backing up our test database via Dbexport. Their are approximately 90 tables in the database. I wrote a korn script that run manually (Im signed on as Informix) it unloads all 90 tables. When I run this script (which does other things, for example, deletes the unload from 3 days before - I only retain 3 days of backups) via cron, for some reason it only unloads about 60 tables and continues on with the script. The script does not cancel it just stops at the 60th table and continues to the next command. I looked at the 'dbexport.out' listing, and there is no error. It just shows the last table it unload. The crontab I set up is in my subdirectory under the /usr/informix subdirectory. I ran a SQL select agaisnt the system catalog, to list the tabname and tabid (its either the tabid or tabnum) of tables in that database. The tabid starts at 100 and ends at 190. The cron job only unloads tabid, 100 through 160. Tables with tabid of 161 through 190 are not unloaded. Does anyone know what I need to do so cron unloads them all? Thanks.