Index: wp-admin/menu.php
===================================================================
--- wp-admin/menu.php	(revision 14044)
+++ wp-admin/menu.php	(working copy)
@@ -119,6 +119,12 @@
 	$ptype_menu_position = is_int( $ptype_obj->menu_position ) ? $ptype_obj->menu_position : $_wp_last_object_menu;
 	$menu_icon = is_string($ptype_obj->menu_icon) ? esc_url($ptype_obj->menu_icon) : 'div';
 	
+	// if $ptype_menu_position is already populated or it is equal to core menu_position loaded below, recurssivly increment
+	$core_menu_positions = array(59,60,65,70,75,80,85,99);
+	while( isset($menu[$ptype_menu_position]) || in_array($ptype_menu_position , $core_menu_positions) ){
+		$ptype_menu_position++;
+	}
+	
 	$menu[$ptype_menu_position] = array(esc_attr($ptype_obj->label), $ptype_obj->edit_type_cap, "edit.php?post_type=$ptype", '', 'menu-top menu-icon-posts', 'menu-' . sanitize_html_class($ptype), $menu_icon);
 	$submenu["edit.php?post_type=$ptype"][5]  = array( __('Edit'), $ptype_obj->edit_type_cap,  "edit.php?post_type=$ptype");
 	/* translators: add new custom post type */