lines dissappear

I am a beginner user of Elements, version 8 (had a old copy laying around).  I recently purchase a stylus pad (xp-pen G640).  When I try to draw a line on either the base layer photo or a new layer, the line is drawn and then it disappears.  This now occures with both the stylus pad and the mouse also connected.  This did not occur prior to attaching the stylus/pad.