+ /* if sfd_state is 1, then we fell through, but at the time of
+ * saving the time stamp the SFD was still high. Thus, the timestamp
+ * is valid.
+ * if the sfd_state is 0, then either we fell through and SFD
+ * was low while we safed the time stamp, or we didn't fall through.
+ * Thus, we check for the time between the two interrupts.
+ * FIXME: Why 10 tics? Seams like some magic number...
+ */
+ if ((sfd_state == 0) && (time - m_prev_time < 10) ) {