Not so much a problem, but more I hope a solution if you have this problem. I am working with Joomla using MAMP and had a component which required ioncube loader.
After a few abortive attempts I submit this as a working solution (well it works here!).
Download the file ( ioncube_loaders_dar_x86.zip ) note that there are 2 potential files on the site X86 and X86_64 I'm using an Intel Core 2 Duo and the x86 is the one that worked for me. (
http://www.ioncube.com/loaders.php)
Expand and copy the file ( ioncube_loader_dar_5.2.so ) into the -> Applications/MAMP/bin/php5/zend/lib/ folder.
Open the file -> Applications/MAMP/conf/php5/php.ini
Add this line -> zend_extension=/Applications/MAMP/bin/php5/zend/lib/ioncube_loader_dar_5.2.so at line 1085
Stop and start the servers and the component now works like a charm!
At this point I should say that my MAMP is running the "out the box" settings and I've got a pretty well "plain vanilla" 10.5 installation. So I'm making the assumption that you are also running with php 5.2 and thread safety disabled.
Hope this helps sombody.