It's a very old question, but I had the same problem right now and I want to share the solution (other answer didn't help me).
If you are porting your joomla instalation you need to check all packages related with PHP in source and destination hosts.
If you are using debian based linux you need to type in both of them:
dpkg -l | grep "^ii php5\?-"
And test that there is the same packages installed. If not, you can type this on source host:
echo $(dpkg -l | grep "^ii php5\?\-" | cut -d " " -f 3)
Copy the result and paste it on destination host (if you are using an SSH client, for example):
apt-get install php-mail-mime ... (lot of packages) ... php5-curl
Or you can try this:
apt-get install $(ssh source_host dpkg -l | grep "^ii php5\?\-" | cut -d " " -f 3)
Check that source_machine is correct (and use root@source_host or another_user@source_host if needed).
Restart apache2 server (it's not necessary, but it's for safe):
service apache2 restart
And check again.
If you are using windows check enabled extensions after and before migration (upload a "info.php" file to test them) and change php.ini according. Later restart apache2 service as administrator using services.msc or command line:
net apache2 stop
net apache2 start
I noticed the mistake when installing again from start and failed requirements checking.
Hope this will be useful to people with same problem.