Website innaccesible! Someone changed the file permissions!

[#1]

Hi,
I have a website which I built for my girlfriend which is hosted in my CCGI space.  I just tried to access it and I get the following message:
CCGI encountered a system error:
When: Cannot change to user's CGI directory via chdir()!
Error Message: Permission denied
Error Number: 13
Server Data:
    Server Administrator/Contact: support@plus.net
    Server Name: www.sparklecinderella.co.uk
    Server Port: 80
    Server Protocol: HTTP/1.1
    Virtual Host: www.sparklecinderella.co.uk
The index file for the webpage is index.php, which has never caused any problems before.  Trying other things I've found that other types of pages *are* accessible, just not PHP pages.
There's another site I've built in the same CCGI space, where PHP files *do* work.
Connecting via PuTTY, I find I can't access the website's home folder (/sparkle).  This is what I get:
drwxr-x---  2 paulyeoman cgiusers 4096 Jun 29  2005 cgi-bin
drwxr-x---  7 paulyeoman cgiusers 4096 Oct 28  2006 crouch
dr----x--T  7 paulyeoman cgiusers 4096 Aug  5 18:47 sparkle
So permissions changed yesterday at 18:47 - but not by me!  I haven't modified the site since April or May.  I haven't told anyone else my password either.  I don't know what the T at the end of the permissions list means.
******
Phew!  I just did chmod 750 on the sparkle folder and now everything seems to be working again.  But how on Earth did the folder permissions get changed anyway?
Thanks,
Paul

[#2]

Changing the permissions on a director or file does not change the last modification time. What it is showing is something had changed within the directory AND the permissions were changed.
If you look in the sparkle directory, do you see any other files with that date/time which mat give a clue as to what changes were made?
You need to raise a ticket and get it investigated and the date/time is important to the investigation so include that as well.
The T is called the sticky bit and alters who has permission to do things in the directory. Thinking about this its possible the directory permissions may have got  corrupted some how but it still needs to be reported & investigated. in case PN were doing anything around that time.

[#3]

Thanks Peter,
I've raised a ticket describing the problem and included a link to this thread.
I'm not able to check in the sparkle folder from work, but I'll do so when I get home tonight.  Hopefully it's just a mistake on PlusNet's part rather than anything malicious.
Cheers,
Paul