Z_ChangeStockCode.php does not rename image file

[PakRicard]

Tim replied by email:

I am going to guess that it is not the rename that returned completed,
but that actually it is the file_exists() that is returning false, as
this returns the same completed message. Can you try changing the
message for when the file_exists() fails, and so it will help narrow
down the problem.

Is this a windows machine?

Thinking about this further, I suspect the hoster is running php <=5.3
and is running it in safe mode (safe mode is removed in >5.3). This
file_exists() check is unnecessary really as obviously the rename will
just have no affect if the file doesn't exist. I suggest you try
removing that check and seeing if it works then.
---------------------------

Thanks Tim:

Already checked it out, and the file_exists() is working fine (as it does all over webERP when looking to read the image file, as in stocks.php), I replaced the echo text and the problem relies on the rename() function, I guess.

It is a windows client machine but weberp lives in a unix server machine, so interpreted in a unix environment.

PHP version 5.2.17
MySQL version 5.5.23-55

Could it be a permissions problem? 0644 is ok?