diff -ruN bash-4.2-10.ori/subst.c bash-4.2-10.new/subst.c
--- bash-4.2-10.ori/subst.c	2011-06-21 15:46:26.000000000 +0100
+++ bash-4.2-10.new/subst.c	2011-06-24 17:50:44.000000000 +0100
@@ -1266,6 +1266,7 @@
 	  continue;
 	}
 
+#if 0
       /* Process a nested command substitution, but only if we're parsing an
 	 arithmetic substitution. */
       if ((flags & SX_COMMAND) && string[i] == '$' && string[i+1] == LPAREN)
@@ -1275,6 +1276,7 @@
           i = si + 1;
           continue;
         }
+#endif
 
       /* Process a nested OPENER. */
       if (STREQN (string + i, opener, len_opener))