I logged as root and tried to change permission for directory to drw-rw-rw- so i used:
chmod 666 dir_name

result i got drw-r--r--

strangest thing is- i can change the permission for this dir. but i cannot set it to "write by all" mode... and i do need it for PHP file upload...

Ideas?

ok, i dont remember the numbers, but u can try chmod a+rw for everyone to have read write access to it.

Using a+rw its the same as 777 - unfortunately for me its the same result cant set write permission for others (except owner - owner is set to full- both read+write+exec)

hmm...intersting..
maybe u could try changing the owner?
chown user file
where user is the username u want to have the ownership and file is the directory or file.
try changing the owner and then changing the permissions.

Incidentally - if your directory doesn't have execute permissions, it won't work....you execute a directory when you cd into it:

[me@localhost ~]$ mkdir try_this
[me@localhost ~]$ cd try_this/
[me@localhost ~/try_this]$ touch a_file
[me@localhost ~/try_this]$ ls -l a_file
-rw-r--r-- 1 me users 0 2005-07-19 06:44 a_file
[me@localhost ~/try_this]$ cd ../
[me@localhost ~]$ chmod -x try_this/
[me@localhost ~]$ cd try_this/
bash: cd: try_this/: Permission denied
[me@localhost ~]$

So when you get this figured out...777's going to be the way to go, not 666 :-)

are you (just a guess) trying to change permission on a filesystem that is not supporting permission ( like FAT32/NTFS/SMB/NFS/... ) ?

I bet it's a problem with the permissions that are already set, preventing you from modifying the permissions on the directory. Make sure you have read, write, and execute permissions for the parent directory first. If you don't, then set them (chmod o=rwx /path/to/parent), and try chmoding the directory you want again. If it still doesn't work, try adding just execute permission for you first, then try adding the read-write permissions for everyone. If THAT doesn't work, then I have one last idea - it could be that something with umask is causing the issue. Try setting umask to nothing (umask 0000) and then try chmoding your directory. This probably shouldn't happen - it's only supposed to work this way if you don't specify an access class in chmod (like chmod +x for example).