[TYPO3-english] Help with permissions and extensions

[Piers temp account]

Hi everyone, help would be massively appreciated - further to my  
previous post:

It's gone a bit wrong for me since I started trying to mess around  
with the direct mail cron file, dmailerd.phpcron. I got the ownership  
of this file changed, then changed it back to it's original state,  
without changing anything in the file.

Now, and I don't know why, I get this error when trying to edit  
extension files (any extension file, not just this one) -

Warning: fopen(/home/wwwcity/public_html/typo3conf/ext/direct_mail/pi1/ 
locallang.php) [function.fopen]: failed to open stream: Permission
denied in /home/wwwcity/public_html/t3lib/class.t3lib_div.php on line  
2687

Also, Direct Mail has stopped fetching html and plain text content,  
which may be related.

Can anyone tell me what's going on, and if I've triggered something  
very bad.

Thanks,

Piers Aitman