Attachments in the filesystem - Unable to write

[MrEyes]

I have just migrated my site from a Windows server to a CentOS server.

When I attempt to set the attachment storage location I get the following error:

We attempted to write a test file to /path/to/my/attachments/directory, but we were unsuccessful. Please verify that the web server has write/delete permissions for this path.

A couple of relevant things:

• This directory is chmod'd to 777 (drwxrwxrwx 12 siteusername psacln 122 Nov 13 10:10 forumattachments)
• PHP runs in safe mode but safe mode uploads to /tmp are enabled in ACP
• /tmp is chmod to 777 (drwxrwxrwt 3 root root 120 Nov 13 05:11 tmp)
• This is a dedicated server
• I get the same error on all the other storage locations so i assume this is a server/config issue

So anybody got any ideas on what to check next?

EDIT: The server is allowing uploads as I have the DownloadsII mod installed and this is working fine
EDIT: Also getting this "Failed to write css files. Please make sure that the directory 'clientscript/vbulletin_css' is writable.Done." when attempting to save CSS with store in filesystem enabled - It seems that it is possible to create directories but not files