Write error

[122christo]

I've build the prog and reading works quite well.
Trying to write a 26c32 (NMC27C32BQ200) gives a write error:
"Load from /home//...//99621C.bin file
Readed 4096 bytes
Writing 4096 bytes to chip...
Writing error"

After this there were some data on the chip. (Befor it was erased.) In a hex editor I read in ASCI:
"Error on block 16..received 2.....1.. .........6..01 ..."
These 6..1 repeats all over the chip with some distance.
Where should I look for the bug?