Strange error on codeigniters LOG

[eluser]miguelp[/eluser]
I'm developing a cms system for a client, and i think that it would be usefull to write it using modules (matchbox), I'm running the latest version of code igniter 1.6.1 on a Linux server using Apache 2.0 and PHP Version 4.3.10-18 (client's server) and i was looking at the logs file to see if there's any erros, and i found this one:

Code:

DEBUG - 2008-03-14 06:17:21 --> ---Matchbox---
ERROR - 2008-03-14 06:17:21 --&gt; Severity: Warning  --&gt; chmod() [<a href='function.chmod'>function.chmod</a>]: Operation not permitted /var/www/askmelisboa/system/libraries/Log.php 112

there is a lot of them on the file so i guess this error gets fired up every time the library log.php is called.
i checked what the file does on that line, and the line is part of the function "write_log" and after it write the file try's to change the file permitions to 0666

Code:

@chmod($filepath, 0666);

the logs folder is set to 0777 so it can be written, so what's causing this error?
and how to fix it?
It dosen't have anything to do with matchbox it self it happens with other files, basically every time the log.php get's called, but anyway hope you can help me out to find a solution.

Thanks in advance
miguelp