diff -urpN src/gdb/sentinel-frame.c dev/gdb/sentinel-frame.c
--- src/gdb/sentinel-frame.c	2008-01-01 23:53:12.000000000 +0100
+++ dev/gdb/sentinel-frame.c	2008-02-15 10:07:36.000000000 +0100
@@ -54,7 +54,7 @@ sentinel_frame_prev_register (struct fra
      onto the corresponding hardware register.  */
   *optimized = 0;
   *lvalp = lval_register;
-  *addrp = register_offset_hack (current_gdbarch, regnum);
+  *addrp = register_offset_hack (get_frame_arch (next_frame), regnum);
   *realnum = regnum;
 
   /* If needed, find and return the value of the register.  */