--- /usr/src/avr-libc-1.2.0/libm/fplib/fp_merge.S	2004-11-10 17:04:46.000000000 -0400
+++ fp_merge.S	2005-01-08 18:00:28.993056542 -0400
@@ -82,6 +82,9 @@
     SBCI  rA2,0xFF
     SBCI  rA3,0xFF
  fp_merge200:                ; pack expanded FP number
+    ;Check if number is NaN
+    CPI     rA2, 0xC0
+    BREQ    fp_mergeNaN      ; just return if it is NaN
     ROL     rA2              ; MSB is hidden 1
     ROR     rA3
     ROR     rA2
@@ -89,6 +92,8 @@
     RET
  fp_merge300:
     RJMP    _U(__fp_zero)   ; merge segments
+ fp_mergeNaN:
+    RET;
 
           ENDFUNC