I posted this question originally under General Problems. As yet not having any look I think maybe it IS a server issue.
My problem is when I edit the config.php file of any of the theme directories the link to styles.php seems to get broken and I get a (brief) '...header information already sent...' error page when logging in. This happens no what I do to theme/mytheme/config.php. If fact all I have to do id open the file in my servers cpanel File Manager for editing and save it again (without any edits) it causes this break.
The result is, I can change the colours in the config.php and they wil be updated when I run Moodle but control over styles.php is lost. And login seems to malfuntion.
Any advice here would be wnormously appreciated.
Thanks in advance.