See: http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=615843

Index: w3m-git/form.c
===================================================================
--- w3m-git.orig/form.c	2011-02-28 15:03:36.000000000 +0100
+++ w3m-git/form.c	2011-02-28 15:32:33.000000000 +0100
@@ -196,7 +196,7 @@
 	if (!strcasecmp(typestr, _formtypetbl[i]))
 	    return i;
     }
-    return FORM_UNKNOWN;
+    return FORM_INPUT_TEXT;
 }
 
 void