Can L293D be replaced with SN754410NE?
This is caused because the SN754410 H-Bridge does not have diodes.  Although the data sheet shows diodes on the drawing, they are ESD diodes which could probably explain your issue.  The SN754410 is however compatible pin for pin with the L293.  The reason is because those do not have diodes.  The L293D however is also compatible pin for pin and has diodes, hence the "D" in L293D.