Yes, that's the problem.
This simple example reproduces the issue. You can skip the calibration by pressing the Esc key, then pylink.closeGraphics() closes the graphic and the Vizard splash screen is shown a second time.
Code:
import viz
import pylink
SIZE = ( viz.getOption('viz.monitor.width', type=int), viz.getOption('viz.monitor.height', type=int) )
viz.go(viz.FULLSCREEN|viz.QUAD_BUFFER)
gallery = viz.add('gallery.ive')
eyelinktracker = pylink.EyeLink(None)
eyelinktracker.sendCommand("screen_pixel_coords = 0 0 %d %d" %(SIZE[0], SIZE[1]))
#eyelinktracker.sendMessage("DISPLAY_COORDS 0 0 %d %d" %(SIZE[0], SIZE[1]))
pylink.openGraphics((SIZE[0], SIZE[1]),32)
eyelinktracker.doTrackerSetup()
pylink.closeGraphics()