I have a problem with my site running with suphp. I noticed that content of iframe on one of my webpages doesn't load. When I try to open this address directly it gives Internal error 500. When I switched to fast cgi this particular page loaded, but rest of my site didn't (I set suphp mode intentionally).
In /var/www/mysite.com/log/error.log file I see:
[Mon Sep 17 23:24:03 2012] [error] [client xxx.xxx.xxx.xxx] Premature end of script headers: tb_tinymce.js.php, referer: ......../pages/edit_form/61
[Mon Sep 17 23:24:04 2012] [error] [client xxx.xxx.xxx.xxx] SoftException in Application.cpp:564: Directory "/var/www/clients/client4/web5/web/media" is writeable by group, referer: ........./pages/edit_form/61
It is strange, because manually created file phpinfo.php also doesn't display. On the other hand there are some php files which returns
"This text is generated by __call. If you expected the index page, you need to use: welcome/index//tinybrowser/css/slyle_tinybrowser.css.php"
which looks like site framework message.
File permissions and owners look ok.