OMG! You got it!!!
OK, so everything's OK now, everything's good but what can I do to correct this SSL certificate. I just noticed I had 3 certificates stacked on each other in this file, just after the RSA key, which seems very strange to me. Could it be the problem?
Thank you very much for your help again! You're saving me so much time and pain finding this. I bought the ISPConfig documentation but couldn't figure out a solution for this problem...
Any idea to fix this certificate?