RAM corrupted battery backed system

hi, i�m working over a rabbit system with flash(512K) and RAM(512K) battery backed.
Sometimes, random, the Ram memory has some data (NOT all) change on start when you plug to power the system.
I�m using softools compiler.

the var TEMP1 only was sometimes with different value on power up
#pragma seg (FARDATA,CREDITO)
far long TEMP1= 0;
far unsigned long TEMP2= 0;
far long TEMP3= 0;
far long TEMP4= 0;
far unsigned long TEMP5= 0;
far unsigned long TEMP6= 0;
#pragma seg (FARDATA)
i don�t write it in code, battery charge is fine.
i read about a bug in the micro TN302.pdf and i wonder if that could be happend to me for example:
ioi ld a,(176)
;135 outi (TBM1R,offset >> 2);
.debug # 135
ld hl,(@21)

          ioi ld	(179),a

;138 offset += 1023;
.debug # 138
ld de,0x3ff
add hl,de
this lines are from the .asm files generated by the compiler.
i hope you can help me