Allowed memory size exhausted after importing PO file
Generating/exporting Feature modules takes a lot of memory, depending on amount of components which you're trying to export. The Features module is constantly improving, so please check the recent stable version if that makes the difference.

Otherwise you've to increase your PHP memory limit either in your php.ini or before the import, temporary add this line into your settings.php file:

ini_set('memory_limit','1G');


If you would like to debug what takes so much memory, then you need to use PHP profiler such as XDebug (xdebug.profiler_enable=1) or use XHProf.