Hi again Markus, I've checked my own logs and found SSL handshake failures starting on April 8th, or the day after Heartbleed was disclosed, as can be seen below with the number of errors per day :
# err date 2 Mar 27 2 Mar 28 1 Mar 29 2 Mar 30 3 Mar 31 3 Apr 1 7 Apr 2 1 Apr 3 2 Apr 4 8 Apr 5 24 Apr 6 2 Apr 7 619 Apr 8 2 Apr 9 2 Apr 10 158 Apr 11 6 Apr 12 2 Apr 13 158 Apr 14 157 Apr 15 168 Apr 16 109 Apr 17 7 Apr 18 7 Apr 19 7 Apr 20 110 Apr 21 497 Apr 22 123 Apr 23 Interestingly, my version was neither upgraded nor restarted during this period, so it cannot be caused by a code change, and is very likely caused by bots trying the attack. So I think it's also possible that you're experiencing the same things and that you didn't notice them before upgrading and checking your logs. Hoping this helps, Willy