We had a moodle site running on a Centos unix server.
I tried to use the certificate module on this server and had the following problem: the certificate module worked well ... BUT ... when I tried to restore a course the restore procedure crashed. I already asked about it here: http://moodle.org/mod/forum/discuss.php?d=140394#p613870 .
As I did'nt get any answer, I started to wonder: as the certificate module comes in a zip, should this module works just with a windows server?
Then I installed a moodle in a windows server and the certificate worked and also the restore procedure worked. It seams very strange to me that this module just work in a windows server and that I couldn't see this in any post or documentation.
So, I'm here again asking if somebody can help me to understand this subject ;)