Too much ink dryer
Avoid the use of additional dryers especially when printing both sides of a sheet.
Backing up a job too soon
Work and turn jobs are most likely to gloss ghost. If possible, allow 24 hours between printing both sides.
Wrong side run first
Run the heaviest coverage side first and allow it to dry for 24 hours.
Over stacked loads
Run the job in several small lifts. This will allow gasses to escape.