Hi!
I'm trying to install a php product that requires ioncube loader. I have followed several guides (they are all the same) for how to install it.

Running ioncube-loader-helper.php tells me the location of the php.ini file. The server has a set of ioncube loaders, and the helper tells me i need version 5.2, which is there. There are no zend extension lines in php.ini, so at the very bottom of the file i insert the line as it says.

Ths is the line:
zend_extension=/usr/local/lib/ioncube/ioncube_loader_lin_5.2.so
i also tried:
zend_extension="/usr/local/lib/ioncube/ioncube_loader_lin_5.2.so"

I restarted apache2 each time. Finally I delibaretly tried to cause an error by inserting some random characters in php.ini and restarted apache2, and it didn't even react. Since ioncube-loader-helper found the same php.ini file as I was editing, I thought the file must be correct. Any ideas?

php version: 5.2.6-2ubuntu4.5

Try restarting your machine. I find (On Windows, though, not Ubuntu) that even if I restart apache, the php.ini doesn't update until after a restart.

unfortunately it doesn't work

I just had a very similar problem. It turned out that someone had tried to install the x64 version of ioncube loader on a 32-bit host. When I installed the 32-bit version, the loader loaded OK.

yes it was the same problem for me...the thing to do was to check the apache log, and there it would tell the problem.