AVR-Chat

I implemented a flash burner for AT29C256 using XMODEM protocol with 
8515 and STK200. Xmodem (checksum) uses 128 byte page size while the 
Atmel flash eeprom use 64 byte page size. So I use for loop (~40000 
iterations, null body) for delay after writing the data into flash. 
However, my program freezed in the second delay loop. It can't be 
because of TeraTerm Pro, it should wait the ACK byte for a second or 
so? Could it be a WDT issue? I used gcc-avr, and the code from 
xnutboot.c (converted to 8515). Also I called wdt_disable() in the 
beginning.