There are two adjustments that can help relieve head strikes.  

1) Increasing Media Suction:

Menu --> Media Setup --> Customize Settings --> Current Settings --> Advanced Settings --> Media Suction (1 = weakest, 10 = Strongest)

2) Adjusting the Platen Gap (raising the head height)

Menu --> Media Setup --> Customize Settings --> Current Settings --> Advanced Settings --> Platen Gap 

You will see these choices:

1.6 Adjusts the gap between the media and

the print head. Select 1.6 (default) for

most media. Select 2.0 if your printouts

are scratched or smudged. Select 2.5 if

printouts are still scratched or smudged

after selecting 2.0.

Note: Choosing a larger gap than

necessary can cause ink stains inside

the printer, reduce print quality, or

shorten product life.