See https://bugs.gentoo.org/show_bug.cgi?id=471270

--- a/poster.c	2013-05-25 21:41:53.000000000 +0200
+++ b/poster.c	2013-05-25 21:43:41.000000000 +0200
@@ -812,8 +812,12 @@
 			if (!strncmp( c, "(atend)", 7)) atend = 1;
 			else
 			{	/* pass this DSC to output */
-				puts( buf);
-				dsc_cont = 1;
+				/* if it is not another DocumentMedia comment */
+				if (strncmp( buf, "%%DocumentMedia", 15))
+				{
+					puts( buf);
+					dsc_cont = 1;
+				}
 			}
 		}
 		else if ( !strncmp( buf, "%%Pages:", 8 ) )