It is realy fixed in MR6:
Firmware Version Fortigate-50A 2.80,build292,041116 [Update]
Antivirus Definitions 4.509(11/19/2004 15:52) [Update]
Attack Definitions 2.151(11/19/2004 11:00) [Update]
Have a nice upgrade ;)
I have 2 FG-100s that have currently been up and running for 38 and 42 days. They are both running 2.80 MR5. The last time either of them was down was when I did the updates to MR5, I just did them on different days.
The Fortinet Security Fabric brings together the concepts of convergence and consolidation to provide comprehensive cybersecurity protection for all users, devices, and applications and across all network edges.